Re: [Emc-users] Newall DRO integration
On Fri, May 11, 2018, at 11:16 PM, Chris Albertson wrote: > I looked at the unit. It seems like a good idea. It uses inputs from > both the motor's shaft encoders and another encoder on the object that is > being moved, like a linear encoder on the table. > > Question: Let's say I wanted to do this myself. Is there a method that > "everyone" in the machine tool industry uses for combining the reading of > multiple encoders? If not it seems like the perfect application for a > Kalman filter. > > But maybe you don't combine them but use the linear DRO for position loop > and the motor shaft encoders for velocity. > > This is a common problem I think with robot arms. The joint has an angle > sensor but the motor has a shaft encoder. So the control loops might be > nested. > > It reminds my the old saying the "A man with a watch knows what time it is, > a man with two watches is never sure of the time." > We did something like this several years ago at Stuart's shop in Wichita, on a big Giddings and Lewis boring mill. We used two PID loops, with their outputs summed. The position command went to both loops. The feedback for one loop came from the motor encoder, and the feedback for the other loop came from the linear scale. The motor loop was tuned as normal, except that the I-gain was kept at zero. The linear scale loop was tuned using ONLY I-gain. So the linear scale loop corrected the fairly small steady-state errors due to things like the lead screw heating up (10 foot long screw, it adds up). It also compensates for backlash in the screw, and if there is much of that it leads to disturbances on direction reversal. Isn't going to fix a clapped out machine, but can improve the accuracy of a tight machine. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Ferrite on a shielded cable
On Tue, May 8, 2018, at 7:27 AM, andy pugh wrote: > On 8 May 2018 at 12:20, andy pugh <bodge...@gmail.com> wrote: > > > Should the shield pass through the choke, or should I strip the area > > where the choke is installed? > > Googling for answers to the question I found this (crank?) web site: > https://www.lessemf.com/cellphon.html > Looking at their snap-on ferrrite bead I have a feeling that the > installation shown on the right is actually ineffective? > The routing looks to be pretty-much non-inductive. Yes, that is stupid. Multiple passes thru a bead can increase effectiveness (somewhere between N and N squared), but only if they all pass thru the bead in the same direction. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Ferrite on a shielded cable
On Tue, May 8, 2018, at 7:20 AM, andy pugh wrote: > I have concluded that I have a problem with noise from my (shared by 4 > drives) servo power supply. > The STMBL drive controlling the 4th axis suffers from CRC errors with > the smart-serial control signals and shuts down. > > By the simple expedient of running it from a separate PSU this problem > seems to be eliminated. > (It ran fine all night yesterday). > > I don't see this as a good long-term solution, so I want to get rid of > the noise in the DC supply. This seems like a job for a choke, but the > cables have a braided shield. Which cables have a braided shield? The ones taking DC power from the power supply to the drives? There's nothing magic about those cables - replace them with two suitably sized single-core wires. I would give each drive its own pair of wires. Twist each pair. They should meet only at the power supply terminals, so current for one drive doesn't flow in the power leads of another drive. Running each pair thru one (or more) ferrite cores might help. If you are using two single-core wires, then there are no bulky connectors to deal with and you can use regular ferrite cores instead of the expensive split ones. Is your drive DC supply floating (transformer) or rectified mains? You need to provide a path for the common mode currents that _will_ flow thru the motor-winding-to-frame capacitances. Each time a drive output terminal switches, charge Q = CV will flow from the drive DC bus, thru the stray capacitance, into the motor frame, and then back to the DC bus of the drive. You want to provide a path for the current that doesn't flow through any sensitive ground. I thought there was a PE terminal on the STMBL board, and a pair of small caps connecting it to positive and negative DC bus. But I don't have my boards handy and I can't find the artwork on github. (I can find the kicad files, but not a PDF or other readable snapshot of any particular board version - pet peeve of mine.) If such a PE terminal exists, I would run the a PE lead from each motor frame tightly bundled or twisted with the motor power leads and back to the drive PE. (If the drive doesn't have a PE, I would make one using a pair of 0.1uF or so film caps with suitable voltage and safety ratings.) That provides a low inductance path for common mode current to return from motor frame to drive DC bus. The PE terminals of each drive could be connected to a common control chassis near the drives. The ferrite beads around the DC bus connections to the common power supply would encourage common mode currents to stay in each drive/motor loop instead of wandering off towards the supply and the other drives. > > Should the shield pass through the choke, or should I strip the area > where the choke is installed? If only one end of the shield is grounded, then it can pass thru the choke. However, the shield is at best marginally useful on DC bus wiring, and if grounded at the wrong place, the shield can actually be counterproductive. Are your motor leads shielded? That shield can DEFINITELY be counterproductive, since it acts as additional "motor-lead-to-ground" capacitance. Common mode current WILL flow thru that capacitance every time the drive output switches, and it WILL find its way back to the DC bus. You need to make sure the path back doesn't take it anywhere it shouldn't go. Motor cable shield should be grounded only at the drive end, and directly to the drive PE terminal (capacitor coupled to the DC bus). The motor cable shield can be connected to the motor frame at the motor end (serves as the motor PE conductor). In the ideal case, the motor frame is not connected to the machine frame, so that winding-to-frame capacitive currents are forced to flow back through the motor PE wire or motor cable shield and can't flow thru the machine frame. In many cases, floating the motor from the machine frame is difficult, hence the need to bundle PE tightly with motor leads. Tight bundling reduces the area of the motor-lead-to-PE-lead loop, making that the lowest inductance path and encouraging _most_ of the common mode current to flow in the PE rather than a longer, higher inductance path through the machine frame. Since Q = CV, many of these issues can be glossed over on the typical 48V hobby servo. But as the DC bus voltage goes up, the issues become more severe. At rectified 120V line (170V DC) it matters. At rectified 230V (330V DC) it matters more. And at rectified 480V or 690V (my day job), it becomes huge. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-u
Re: [Emc-users] Going off-grid [Was: Thinking about going off-line eventually.
On Tue, Apr 17, 2018, at 12:53 PM, Chris Albertson wrote: > What I meant was "no fixture" not "better fixture" For example if you > design the room for LED lighting you can design in something like a > crown molding. Then you can runs a LED strip all the aw atone the top > of every wall. > > In a large my cousin tore out all is hanging florescent fixtures and > then directly attached LED strips to the painted ceiling he spaced the > rows of LEDs every 24 inches. It looks bad if yu do this in a living > room but i the garage is is bright as daylight. The strips are > self-adhesive and very easy to use Until the chinese LED strips develop a short somewhere, and the low-voltage but fairly high current power supply overheats the strip. Would not want the strip mounted directly to wooden joists in the garage. There is a reason that even the el-cheapo 4' shop lights are made of metal. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Large servo selection
On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote: > I'd like this to be reasonably low effort. My biggest concern is single > phase input. Control/response requirements are about as low as it gets. > > I'm looking to output about 1000lbf in a linear direction via a > crank/slider or ballscrew with peak speed of about 1m/s. So that's a real > 5hp of energy. Mixed units are making my head hurt 1000lbf = 4448 newtons I think? At 1m/s, that is 4448 watts. 1 HP = 746 watts, so 4454 watts = 5.96HP. A ballscrew would have to spin pretty fast to hit 1m/s. Obviously it depends on the pitch, but a plain vanilla 5mm pitch screw would have to go 12000 RPM (well above critical speed unless very short). Even a 20mm pitch screw would need 3000 RPM. You don't mention the stroke length. Are you moving a few inches in a fraction of a second, or several meters over several seconds? 4.5kW or 6HP isn't going to be small or cheap no matter what you do... > Duty cycle will be low, and external active cooling can be > provided if required. So things like steppers are out, I've never seen a > stepper that outputs nearly that much, and I don't particular want to > create a 4kw 80v dc power supply... > > re: Control requirements, I really only need to start running at a > particular speed and be able to return the system to a somewhat close stop > position, which can be as simple/bad as a vfd with a switch and timed jog. > Any extra control over the system that I can get would add capabilities > though. > > The goal here is to see if there are any industrial drives out there that > might periodically pop up on ebay which are higher KW and single phase > capable.I see units like the Parker Gemini GV/GV6-U12/H20 which claim > single phase at 3.5kw and 5.9kw. > > Dave > > > On Wed, 11 Apr 2018 09:24:32 -0400, Dave Cole <linuxcncro...@gmail.com> > wrote: > > > How much time/work do you want to put into this motor/drive setup? > > There are no really cheap large servo motor solutions unless you stumble > > into a deal on Ebay or a surplus marketplace. > > Larger servos generally mean 3 phase inputs. So that becomes an > > immediate issue. > > > > If you can live with a VFD, your life will be much simpler to simply get > > a single phase input VFD and a suitable motor. > > You can find 3 phase gearbox equipped motors on Ebay that can get you > > 500 rpm max. > > > > Dave > > > > > > > > On 4/11/2018 2:01 AM, David Berndt wrote: > >> Wondering if anyone had any preference/experience/advise to share with > >> single phase capable larger servos. I'm looking at an application for a > >> 3 to 5hp motor with a vfd, but if I could just get a servo to fill in > >> that'd be nice. Gear reduction will be required, but something with > >> more torque, needing less reduction will make things easier.Say ~500rpm > >> as a goal maximum output. > >> > >> I see things like Fanuc red cap servos (ai series? pulsecoder encoder) > >> 2.5kw kicking around ebay. Driving something like that would seem to be > >> the challenge? > >> > >> Thoughts? Suggestions? Previous experience? > >> > >> Dave > >> > >> -- > >> > >> Check out the vibrant tech community on one of the world's most > >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot > >> ___ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -- > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Large servo selection
On Wed, Apr 11, 2018, at 3:08 PM, John Kasunich wrote: > > > On Wed, Apr 11, 2018, at 10:30 AM, David Berndt wrote: > > I'm looking to output about 1000lbf in a linear direction via a > > crank/slider or ballscrew > You don't mention the stroke length. Are you moving a few inches in a > fraction of a second, or several meters over several seconds? On further thought... Ballscrew requires unreasonably high RPM. Crank is very non-linear, and has major problems as stroke exceeds a couple inches - longer stroke means longer crank which means more and more torque is required. You never use more than a half-revolution of the crank, so some serious reduction will be needed between motor and crank. Have you considered roller chain? Keep the sprocket size small so the torque doesn't get crazy high, but you can use multiple revolutions of the sprocket to cover an unlimited stroke. Still going to require a gearbox; for a 1000 lbf load you will need a few thousand in-lbs (few hundred ft-lbs) of torque, which is a LOT for any motor. Interesting engineering problem to be sure. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] (no subject)
On Sun, Apr 8, 2018, at 9:02 AM, andy pugh wrote: > On 8 April 2018 at 13:47, Gene Heskett <ghesk...@shentel.net> wrote: > > On Sunday 08 April 2018 02:00:59 Lawrence Glaister wrote: > > >> https://www.seeedstudio.com/fusion.html for production. Smooth as silk > >> and unbeatable prices. (10 boards 3.8x2.5" for $4.41(March Sale) + > >> shipping). > >> > > Post pix when you get them back please. > > I have used Seeed a few times: > > https://photos.app.goo.gl/f4yBUuQ2WKR7cBfF3 > https://photos.app.goo.gl/cUWqFKAtmTej3UEk1 > https://photos.app.goo.gl/wyVFvXT2BgT9YSY22 This one looks very interesting... some kind of capacitive or inductive encoder? > https://photos.app.goo.gl/ZhbLxEtFG6wNBQ3y1 > > I have always been happy with what I got, they come back in <2 weeks > and you get plating, solder resist and silkscreen. I would need to be > in a real hurry to make my own now. > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] wiring. axis move?
On Sun, Mar 25, 2018, at 8:29 PM, Gene Heskett wrote: > > On Sat, Mar 24, 2018, at 5:54 PM, a k wrote: > > > I measure supply 120 v ac. > > Thats another problem, the std line voltage has been 127 volts for > several decades. I would at least compare what this one reads against a > known good meter, because either your building wiring is wonkie, or that > meter belongs in the trashbin, thats about a 5% error. I beg to differ on that. 127V is NOT the standard and has never been. The standard is 120V, with a tolerance of +/-5% at the service entrance and +5/-10% at the load. See this document: https://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf Or any number of other specs and standards. Or simply look at the nameplate of any appliance or even the top of a light bulb. If you have 127V at your house, you are actually a hair above the +5% tolerance. Maybe your local power company has set the transformer taps a bit high to allow for voltage drop at the far end of the line, and you are stuck with it because you are near the transformer... -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] wiring. axis move?
On Sat, Mar 24, 2018, at 5:54 PM, a k wrote: > I use small tester. > I measure supply 120 v ac. > Meter works. > Axis was moving by them self. THIS: > Touch box with real ground and breaker turn off. Means you have something screwed up. STOP and figure out what it is before you kill yourself or someone else. > Between box and real ground tester read 30 v ac Maybe that means your wiring error is on the secondary side of your power supply transformer. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Getting a burned up polygroove belt out of a motor pulley. Need chemist expert
On Wed, Mar 21, 2018, at 6:45 PM, Gene Heskett wrote: > Greetings all; > > I have a Rikon 10-325 bandsaw. Trying to cut a block of alu with a blade > thats had one side of it dulled, the blade turned and bound in the cut, > and burned the drive belt, a 240J into the motor pulley. Rather > thoroughly welding the kevlar backing into the pulley. > > Does anyone have a recipe for some panther piss that will clean it out, > or am I stuck buying another pulley from Rikon's parts dept? > What is the pulley made of? Steel? Aluminum? Plastic? It's the motor pulley. That means you can spin it up by simply plugging in the motor. I'd try to turn the stuff out of the grooves using a "lathe tool" made of something softer than the pulley. Hand-held, probably with an improvised tool rest, like on a wood lathe -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Bringing the saw beveler back to life
On Mon, Mar 5, 2018, at 10:25 AM, Mark wrote: > At any rate, what the question above is asking, does the correction > happen while the X axis is moving to smoothly blend the adjustment, or > does it try to jump to the correction without blending the two axis's moves? The "lin" in lincurve stands for linear interpolation. So yes, it blends. > Yes, there are groups of X axis stations that have the same offset. What > I'm trying to figure out is how to map those X axis coordinates that are > in that group. If the X axis stations between say 15 and 25 are all the > same, but the next group of X axis stations which are the same between > 26 and 31 are different than the previous group, how would I map that > between the x,y coordinates in the lincurve statements? Example: The error between X=0 and X=4 is zero, then it ramps up to 0.002 at X=5, hits 0.003 at X=6, then remains at 0.003 for the next 8", until X=13. Then it ramps back down to zero at X=14, and hits -0.001 at X=15, where it stays until X=21. So you would use the following X,Y pairs: 0, 0.000 4, 0.000 5, -0.002 6, -0.003 13, -0.003 14, 0.000 15, 0.001 21, 0.001 You can use up to 16 pairs. Best approach is to plot your measured errors on a piece of paper or in a spreadsheet, then find the set of 16 (or fewer) straight line segments that best matches your measured error plot. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] non-contact position sensors, surprisingly good performance.
On Sun, Mar 4, 2018, at 10:40 PM, Gene Heskett wrote: > On Sunday 04 March 2018 20:23:01 Chris Albertson wrote: > > > I'm not contributing to EMC development so I have no say in how to do > > it. But I'd suggest a move to Github. Not just because they are > > stable but because Git offers a better way to work > > > > On Sun, Mar 4, 2018 at 10:36 AM, andy pugh <bodge...@gmail.com> wrote: > > > On 4 March 2018 at 18:00, Peter Blodow <p.blo...@dreki.de> wrote: > > >> This mail has been sent to sourceforge this morning and was > > >> returned without reason. > > > > > > Yes, Sourceforge is having problems. > > > > This, I'm afraid, is symptomatic of a site thats well on the way of going > broke. We should get used to the idea of doing it ourselves, before the > whole code base disappears. They have already lost the Nitros9 code base > and can't seem to find it, its an hg repo, and its been months since > I've been able to refresh my copy with an hg pull. > > Contingency plans are in order. > Just to clarify a few things: The code base is absolutely not at risk. The LinuxCNC code was moved off of Sourceforge years ago. It was on a privately hosted git server for a while, but was moved to github several months ago. The LinuxCNC website is also NOT on Sourceforge. I'm not exactly sure where it is hosted now, but it hasn't been at SF for years. The only thing we use Sourceforge for now is the mailing lists. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] CSS and spindle-at-speed during a G33
On Wed, Feb 7, 2018, at 2:35 PM, Chris Albertson wrote: > The G33 says to do a synchronized move. This is physically impossible. > The Z axis has some limit on it's ability to go from zero speed to the > commanded speed. So the controller is reducing the spindle speed so as to > match the ability of the z-axis motor. Minor (or maybe not) nit to pick here. G33 is NOT like other multi-axis moves. LinuxCNC will NOT reduce the spindle speed based on the limits of your Z axis. You need to choose a spindle speed and thread pitch that are within the capability of your Z axis. You also need to start far enough away from the part that Z will be able to accelerate to match its target speed before it starts cutting. A concrete example: you want to cut a 1/4"-20tpi thread (0.050" lead) at 1000 rpm. Your Z axis needs to be able to move at least 0.050 x 1000 = 50 ipm. If it can't, you will get a bad thread and maybe a following error depending on how your limits are set. In practice, you really need some margin on Z speed, at least 10-20%. > ALL multi-axis moves are this way. You see it best on a milling machine > where perhaps the z-axis is also the slowest. Say you are milling a 45 > degree ramp that climbs upward to the left. The X motor would have to slow > to match the max speed of the z motor. > > When a lathe cuts threads it is in real-life cutting a ramp. The spinach is > turning in x-direction the carnage in z. You can only cut as fast as the > slowest motor can move. And nether of the motors has infinite acceleration. > > On Tue, Jan 30, 2018 at 2:42 PM, <tom-...@bgp.nu> wrote: > > > We have CSS on and are threading with a G33 on our Emco lathe and we are > > seeing the spindle decelerating during the cut. Seems like the spindle > > speed should be fairly steady at a given X location during a G33 and what > > it seems like is that the spindle is still decelerating to speed while it’s > > in the cut rather than before the cut. > > > > We are rapid-ing (G0 in Z) out of the part at the center of the part (X=0) > > and so CSS spins the spindle up to full speed as I’d expect (*) but it > > appears that our spindle is still decelerating to speed as the next > > threading pass is happening. We read that G33 will wait for > > spindle-at-speed before looking for the index pulse. But our > > spindle-at-speed signal seems to be high during the full cycle once the > > spindle speeds up the first time. It seems like spindle-at-speed should go > > low after rapiding out of the part as it moves to it’s next X location and > > decelerates to it’s next speed at the cutting diameter. Or are we > > misunderstanding spindle-at-speed when CSS is in effect? > > > > > > (*) Is it normal that a G0 move also triggers CSS to spin up (or down)? > > Seems like the trajectory planner would know where the next cutting move is > > and not adjust the spindle speed until it needs to. In our case we are > > rapiding out of the part at X=0 and the spindle speeds up when it doesn’t > > really need to. > > > > -Tom > > > > > > > > -- > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > -- > > Chris Albertson > Redondo Beach, California > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Unsubscribe from the Emc-users list
On Wed, Feb 7, 2018, at 12:01 PM, Avi Shishe wrote: > Hi, > > I try to unsubscribe from the Emc-users list without success. I do not > receive any message to my mailbox to complete the process. > Please advise what I can do to reach my goal. Since you tried yourself first and were unsuccessful, I logged in and took a look. (I'm a list admin.) There have been changes to the privacy laws, so the list software no longer allows even a list admin to see the email addresses of subscribers. I told it to unsubscribe "pv776shi...@gmail.com", and it replied "If the email address you entered was subscribed, it has now been unsubscribed". So even now I don't know if it worked. Let us know if you continue to get messages (and make sure to give the exact message that the list is sending to). Regards, John Kasunich -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] unsubsribe please
Go to https://lists.sourceforge.net/lists/listinfo/emc-users and unsubscribe yourself. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] The sound of G1 vs G33 moves
On Tue, Feb 6, 2018, at 10:37 AM, tom-...@bgp.nu wrote: > In an effort to optimize our lathe for spindle synchronized motion a > question came up. Should a machine sound the same when running a G1 vs > G33 at identical feeds and speeds? > > When we spin the spindle at, say, 800 rpm and command a G1 move in Z at > 80 ipm the machine sounds different from a G33 move at those same > speeds/feeds. When you say "same feeds and speeds", do you mean you have selected the F and K and S values such that the actual Z axis speed should be the same? The speed of the Z axis on a G1 move is based on the F word (feed rate) in effect at that time. If you are doing "normal" feed, the F word is in inches per minute (or metric equivalent) and does not depend on spindle speed. If you are doing feed-per-rev, it is F inches per rev of the spindle, and does depend on the spindle speed. The speed of the Z axis on a G33 move is based on the K word (thread pitch) in effect at that time, and always depends on the spindle speed. So in general, those moves will not "sound" the same, since they are at different speeds. Some specific examples Normal feed mode: G94 (set normal feed mode) F6 (set feed to 6" per minute) G1 Z2 (Z moves at 6" per minute, regardless of spindle speed) Feed-per-rev mode: M3 S800 (start spindle at 800 RPM) G95 (set feed-per-rev mode) F0.004 (set feed to 0.004" per rev) G1 Z2 (Z moves at 0.004" x 800 = 3.2" per minute) Spindle sync mode: M3 S800 (start spindle at 800 RPM) G33 Z2 K0.020 (Z moves at 0.020" x 800 = 16" per minute) If you've chosen the F, S, and K values so that the Z axis speeds should be the same, then it gets more complicated. How is your spindle speed set? Do you have a closed loop control such as a VFD with encoder feedback? Maybe (especially if you just have a constant speed motor and gears/belts) the spindle isn't really turning at 800 RPM. In that case, G1 with normal feed will ignore the actual spindle speed and run at the programmed F feed rate, while G33 will track the actual spindle speed, even if it isn't 800 RPM. Do you have a convenient way to independently verify the spindle speed? > Perhaps for the motion planner that is two different code paths but > regardless should the two moves sound identical? G33 waits for index > before moves but once moving is there something going on that would > cause it to sound different than a non-synchronized move? Another possibility is the acceleration up to the cutting speed at the start of the sync move. In some cases, you can have overshoot or speed oscillation as the axis matches speed with the spindle, and that could sound strange. > We are wondering if the difference is sound we are hearing is an > indication of a problem in our spindle or in the way we are tracking > spindle speed. The ultimate way to know what is going on is to use HalScope to view the spindle and Z-axis speeds during the entire move. > > -Tom > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Tell me if I did something right
On Sat, Jan 27, 2018, at 12:43 AM, Gene Heskett wrote: > As for the live centers, I guess I'll have to throw both what > I have and bigger money out for a good one. These 2 $22 ones are sure > junk. I wouldn't use them within 18" of the chuck, I've already had them > make a well tightened workpiece walk in the chuck. At about 10" away. If your tailstock barrel is not aligned with the spindle, any center (including a perfectly good one) is going to make work want to walk out of the chuck. It will force the end of the part to rotate around a point that is not on the spindle axis, and that means the part is being rocked back and forth in the chuck once per revolution. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Off topic: wolfrom drive
On Fri, Dec 15, 2017, at 06:16 AM, andy pugh wrote: > If you look at stock internal gears: > http://www.hpcgears.com/pdf_c33/17.7.pdf > You will find that getting a pair that differ by only one tooth isn't > that easy. And they will differ in PCD. The PCD difference isn't to > hard too deal with in external gears if you can make them big enough > for the corrections not to distort the teeth too much, but it would be > much easier to not have two PCDs on the planets. > So, you would ideally be making your own internal gears. I believe it would be possible to design a similar drive using the same internal gear for both the grounded ring and the output ring. All the gears would have standard tooth forms, and could be off-the-shelf. The trick is that the planet gears centers would have to be at different radii. So instead of the two sets of planet gears running on the same planet carrier pins and being fastened to each other, you would have two sets of planet carrier pins (probably on opposite sides of a planet carrier plate). The planets would all be independent. One set would have N teeth, the other set would have N+1 teeth. The sun gear would be two stacked and coupled gears, one with M teeth (meshing with the N tooth planets) and one with M-2 teeth (meshing with the N+1 planets). Not sure if what I'm describing is still a wolfrom drive, but it would have the same result - a very high reduction from planet to output ring. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] synchronized servo motors with phase control
One thing to be aware of: If your application runs the motors in the same direction for long periods of time, absolute position will keep increasing even though relative position doesn't change. If HAL still uses single precision (32bit) floats, you eventually might start losing resolution. If HAL uses double precision it will probably take a very long time before that happens. But you are still looking at small differences between large (and constantly increasing) numbers - never a good thing. A more elegant solution would involve hacking the Mesa firmware so that each encoder counter accepts counts from two sources: one source is the motor encoder, and the other is a "reference encoder". Every "forward" pulse on the reference encoder increments the position counter, while every "forward" pulse on the feedback encoder decrements the position counter. (And vice-versa for "reverse" pulses.) That way the position counter always tells you the position difference between the reference and feedback, which remains small no matter how long your run the machine. Feed that difference to the feedback input of a PID loop, feed your desired phase angle to the command input, and you are done. If your encoder frequency is low enough to be counted in software, LinuxCNC already has a component called "encoder_ratio" which does exactly that. Just set "master-teeth" and "slave-teeth" both to 1. http://linuxcnc.org/docs/html/man/man9/encoder_ratio.9.html On Wed, Dec 13, 2017, at 04:31 AM, andy pugh wrote: > On 13 December 2017 at 03:21, Ralph Stirling > <ralph.stirl...@wallawalla.edu> wrote: > > We have a project requiring four servo motors run synchronously, with > > the ability to adjust the phase angle between motors. The motors will > > be ramped up and down in velocity (remaining synchronized), but with > > programmable phase offsets. > > This sounds relatively easy. Whatever you do one motor is going to > have to be the reference (zero shift) motor, so program that with a > straightforward velocity PID. > Then the other motors are phased relative to that, and their PID > feedback needs to be difference between the zero-shift motor position > and their own position, whilst their command is the required phase > shift. > > It sounds like you need 4 PID components and three sum2 components > (with negative gain on one input) > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Wrong polarity of pwm?
On Sat, Dec 9, 2017, at 10:31 AM, Gene Heskett wrote: > On Saturday 09 December 2017 05:59:58 andy pugh wrote: > > > On 9 December 2017 at 04:06, Gene Heskett <ghesk...@shentel.net> wrote: > > > So I > > > tried to invert_output on gpio.001, which ack the above, should have > > > done it. > > > > Yes, I agree, it should. > > > > So, did it? > > So, lets see if this will work instead: > > setp hm2_5i25.0.pwmgen.00.out0.invert_output true > > No change, I half expected an init error > 12 bit RW FALSE hm2_5i25.0.pwmgen.00.out0.invert_output Let me get this straight: you typed a "setp" command referencing a parameter (or pin) that you know exists and should be writable, and the command didn't work (meaning it didn't change the value of the parameter)? That is a red flag right there and needs to be investigated. If you can't change the value of a parameter with a setp command something is seriously busted. To be honest, I've never typed out "true" or "false" on a setp command, and I'm not 100% sure that halcmd accepts that. Try just using 1 or 0: halcmd show param hm2_5i25.0.pwmgen.00.out0.invert_output (see what it's current value is) halcmd setp hm2_5i25.0.pwmgen.00.out0.invert_output 1 halcmd show param hm2_5i25.0.pwmgen.00.out0.invert_output (it should be true now) halcmd setp hm2_5i25.0.pwmgen.00.out0.invert_output 0 halcmd show param hm2_5i25.0.pwmgen.00.out0.invert_output (it should be false now) If the above doesn't work, either the driver is writing to the parameter, or something is seriously busted in your install of LinuxCNC. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Determining scale
I'm with Peter that manual turning is simpler. But if you can't turn it manually, here is a simple HAL approach. This takes advantage of the fact that a mux2 with its output fed back to one input acts like a sample- and-hold circuit. Set up one channel of your 5i20 or whatever to count the motor encoder, using quadrature as normal. Do NOT connect the index enable, treat it as a pure 2-phase encoder without index. Set up another counter (either hardware or software) in counter mode to count index pulses only on the spinde. Set up two comparator components and two mux2's in HAL. Both comparators are looking at the spindle count. The first comparator has a threshold of say 1.5 counts. So it's ouput will change state as the second index pulse increments the spindle count from 1 to 2. The second comparator has a theshold of 21.5, so its output will change state as the spindle count increments from 21 to 22. Connect the sel input of each mux2 to the corresponding comparator output. Connect the motor position to one input of each mux2, and connect the other input of each mux2 to its own output. Run the spindle slowly enough that the index pulse is detectable by whatever you are using to count it. When you start out with the spindle position at zero (or negative), both mux2's will be feeding the motor position (first input) to the output, and both outputs will track the motor. When spindle count ticks from 1 to 2, the first mux will switch from tracking the motor to holding its own current value. When the spindle ticks from 21 to 22, the second mux will do the same. The difference between the two captured values divided by 20 is the scale you are looking for. On Fri, Nov 24, 2017, at 11:49 AM, Gene Heskett wrote: > On Friday 24 November 2017 11:04:16 Peter C. Wallace wrote: > > > Why dont you just make an index mark/pointer on the headstock and > > chuck This should be hand settable to less than a degree of chuck > > motion then just note the motor encoder count when the chuck is > > aligned with the mark and then rotate the motor until the chuck has > > turned say 20 turns. This should give you the ratio to within 1/7200 > > which should be better than needed. if thats not enough, just do more > > turns, you could get to PPM accuracy is less time than it takes to > > futz with doing this is hal > > > > Peter Wallace > > Mesa Electronics > > > That might be one way, Peter, and likely less time. But accessing the > motor shaft is going to be difficult, perhaps with pliers on the encoder > coupling. A bent wire in the chuck to use as a pointer. And running the > motor very slowly until that 20th is about to come up would greatly > simplicate that. Then just subtract the first raw-count from the last. > > Better yet would be a counter on the index and just let it run a while. > Then the question is how can I do that. I'll figure out something. That > is what gpio's are for... > > But first, transfer the wiring... > > -- > > Check out the vibrant tech community on one of the world's > > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Tech Shop goes out of business
On Thu, Nov 16, 2017, at 12:39 PM, John Kasunich wrote: > > > On Thu, Nov 16, 2017, at 11:58 AM, Gene Heskett wrote: > > On Wednesday 15 November 2017 23:38:46 Jon Elson wrote: > > > > > It seems that Tech Shop has gone out of business nationally. > > > > > > Jon > > > > That doesn't ring any bells here, Jon, What sort of stuff did they sell? > > > > I think they didn't sell things. They are/were a shop space where people > would > pay a membership fee for access to space, tools, etc. Makerspace kind of > thing. > http://www.techshop.ws/techshop.pdf -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Tech Shop goes out of business
On Thu, Nov 16, 2017, at 11:58 AM, Gene Heskett wrote: > On Wednesday 15 November 2017 23:38:46 Jon Elson wrote: > > > It seems that Tech Shop has gone out of business nationally. > > > > Jon > > That doesn't ring any bells here, Jon, What sort of stuff did they sell? > I think they didn't sell things. They are/were a shop space where people would pay a membership fee for access to space, tools, etc. Makerspace kind of thing. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] One final Q re using a dc spindle motor
On Tue, Oct 24, 2017, at 08:14 AM, andy pugh wrote: > On 24 October 2017 at 12:10, Gene Heskett <ghesk...@shentel.net> wrote: > > > Correct, except encoder.nn.velocity is fed thru a last 4 edges averager > > to remove some of the noise in the encoders output. That unforch also > > affects the spindle to Z phaseing in the G33.1 backout. > > You might want to filter the velociity, but I see no point in > filtering the position, which is what G33.1 uses > > You could also try using the DPLL timer to take jitter out of your > encoder sampling. That's a pretty simple setting with the right > firmware (one that ends in "D" for DPLL) I'm pretty sure Gene's "4 edge average" is dealing with mechanical errors in his homebrew spindle encoder rather then sampling jitter. The 4 edges mean that it averages over a full quadrature cycle and thus deviations from proper 90 degree quadrature phasing are masked. John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Question on mechanical dial accuracy
On Fri, Sep 8, 2017, at 02:19 PM, Gene Heskett wrote: > Greetings all; > > > I have measured the x axis of this lathe quite a few times, and arrived > at an X scale that moves it 1.000 inches according to a dial indicator. > > However, when carving metal it doesn't seem to be correct. > Part of the problem is almost certainly the difference between unloaded moves and loaded (cutting) moves. Tools flex, toolposts flex, machine flexes, etc. When you are trying to set the "scale" of an axis, you want to use the longest travel that you can accurately measure. That minimizes the effect of things like lash, flex, etc. You can't consider the scale on an axis to be correct until you can command multiple different moves and have them all be correct. Command a 0.1", and the dial indicator better say 0.100". Command a 1" move, and the dial indicator better say 1.000". Command a 6" move, and dial calipers or indicator plus a 6" gage block or whatever you can come up with better say 6.000". And you should be able to make and measure a whole sequence of 1.000" moves all the way down the length of your axis. > For instance, the motor pulley I took off the OEM 3/4 horse has a .750" > bore, but the 1 hp motor on it now has a 7/8" (.875") OD shaft, and a > nominally 1" larger pitch diameter, so I undertook to bore the OEM > pulley to .875" yesterday, by first boring it out what I thought > was .1000", which should have taken it out to .850". But I didn't > get .850", more like .824". And had to make about 6 more swags to > actually get it to fit the spare, identical motor. There are probably two things at play here - flex and touch-off error. (Scale error could be happening too, but IMHO you shouldn't cut metal until you've verified scale with multiple measurements as described above.) I find it hard to do a really accurate touch-off on the inside of a bore. And even on the outside (where I gradually back the tool away from the part until a 0.250" dowel pin slips thru the gap), the touch-off is done with no load on the tool and is subject to change due to flex. In your situation, I would do the following: 1) Bring the tool into the 0.750" nominal old bore until it just takes a tiny chip. Touch off X to a radius of 0.375, diameter 0.750. I know this is probably wrong, but it gets me close. 2) Set X to 0.385 (0.010 depth of cut), which should give me a diameter of 0.770. Take a cut on the bore. Get the tool clear and measure the bore as accurately as I can (bore gage, telescoping gage and mic, whatever). That measurement tells me what the machine will do when cutting 0.010 deep. It will be different for heavier or lighter cuts, but I'm planning to finish my job with a 0.010" cut. 3) Reposition the tool back to X = 0.385 (using MDI). Use the touch-off button to reset the diameter to the exact measured bore diameter. Now I'm corrected for flex and anything else, and as long as the tool doesn't wear or something else bad happen I should be good. 4) Make roughing cuts at whatever depth of cut I can do until I get close. Final roughing cut should be at X = 0.4137, that is 0.020 (two passes) undersize on the radius. Measuring the bore after the last roughing cut isn't critical, but I usually do it just as a check. 5) Make my first finishing cut, with X = 0.4275, target diameter is 0.855". This cut is 0.010" deep, just like my calibration cut, so the flex should be the same and it should come out pretty darn close. 6) Measure the bore as accurately as I can. This one really counts. Maybe the tool wore a bit during roughing, maybe something moved, or maybe the flex or screw error is different since we're at a different spot on the axis. This measurement will let me fix that. 7) Move X to 0.4275, exactly where it was when I made the cut. If the measured diameter isn't exactly 0.855", hit the touch off button and set X to exactly half of the _measured_ diameter. This should set me up for exactly one more pass, cutting 0.010, which should have the same flex and everything else as the previous pass. 8) Make my final finishing cut, with X = 0.4375, target diameter 0.875. 9) Measure and hope I didn't screw it up. This procedure is NOT appropriate for production - I stopped and measured twice during the job, and probably modified the g-code a couple times (in some cases I don't even bother with a program except for the roughing, I make the first and final cuts with MDI). But for a one-off like Gene is describing, I've found this process to be the best way to get the diameter I'm aiming for. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http:/
Re: [Emc-users] Question on Z backlash vs rigid tapping
Maybe but it definitely will remove a thin layer of the diamond. and another, and another On Thu, Aug 3, 2017, at 11:55 AM, Stuart Stevenson wrote: > Would that create a thin layer of casehardening? > > On Thu, Aug 3, 2017 at 10:02 AM, John Kasunich <jmkasun...@fastmail.fm> > wrote: > > > It's not room temp when it is scraping across steel at a couple > > thousand surface feet per minute. (Or even a couple hundred.) > > > > On Thu, Aug 3, 2017, at 10:52 AM, Gene Heskett wrote: > > > On Thursday 03 August 2017 06:54:02 andy pugh wrote: > > > > > > > On 3 August 2017 at 07:39, Gene Heskett <ghesk...@shentel.net> wrote: > > > > > Playing with that $12 diamond disk, it looks as if it will do a > > > > > decent job of shaping HSS tooling given time enough to do it. > > > > > > > > You probably want CBN (or conventional abrasive) for HSS. Diamond is > > > > Carbon. Carbon dissolves in steel. > > > > > > At room temps? > > > > > > Cheers, Gene Heskett > > > -- > > > "There are four boxes to be used in defense of liberty: > > > soap, ballot, jury, and ammo. Please use in that order." > > > -Ed Howdershelt (Author) > > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > > > -- > > > Check out the vibrant tech community on one of the world's most > > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > > ___ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > -- > > John Kasunich > > jmkasun...@fastmail.fm > > > > > > -- > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > -- > Addressee is the intended audience. > If you are not the addressee then my consent is not given for you to read > this email furthermore it is my wish you would close this without saving or > reading, and cease and desist from saving or opening my private > correspondence. > Thank you for honoring my wish. > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Question on Z backlash vs rigid tapping
It's not room temp when it is scraping across steel at a couple thousand surface feet per minute. (Or even a couple hundred.) On Thu, Aug 3, 2017, at 10:52 AM, Gene Heskett wrote: > On Thursday 03 August 2017 06:54:02 andy pugh wrote: > > > On 3 August 2017 at 07:39, Gene Heskett <ghesk...@shentel.net> wrote: > > > Playing with that $12 diamond disk, it looks as if it will do a > > > decent job of shaping HSS tooling given time enough to do it. > > > > You probably want CBN (or conventional abrasive) for HSS. Diamond is > > Carbon. Carbon dissolves in steel. > > At room temps? > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Question on Z backlash vs rigid tapping
On Tue, Aug 1, 2017, at 10:34 PM, Gene Heskett wrote:
> On Tuesday 01 August 2017 20:33:11 Ken Strauss wrote:
> > you can use a spiral point ("gun") tap to push
> > the swarf ahead of the tap and out of the bottom.
>
> I think that would describe the tap I am using except the flutes and
> cutting edges are straight.
Then its not a spiral point tap. Sounds like a hand tap. Hand taps are for
hand tapping and shouldn't get near machines.
In fact, I don't even use hand taps for hand tapping. Spiral point taps are so
much better that I would _never_ actually buy a hand tap. The only hand taps I
have are ones I was given.
Hand tap:
https://images1.mcmaster.com/mvA/contents/gfx/large/2521a773p2-a02cl.png
Spiral point tap:
https://images1.mcmaster.com/mvA/contents/gfx/large/2523a413p1-a02cl.png
Spiral flute tap:
https://images1.mcmaster.com/mvA/contents/gfx/large/2529a21p1-a02cl.png
That little notch at the tip of the spiral point tap makes a huge difference!
--
John Kasunich
jmkasun...@fastmail.fm
--
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Re: [Emc-users] Progress, if I spell it right
On Fri, Jul 21, 2017, at 08:56 AM, Gene Heskett wrote: > But another problem I have mentioned previously ate my lunch, about 2 > hours and some material yesterday while making the first 8 brass screws > for the rear of the spindle spider. Axis couples the 4 motion keys to > the two teeny little tally eyeballs at the top of the axis left control > panel. So you can set the speed to creep, run it to the reference > position, and do a touch off which is automatically applied to the last > axis moved. > > But HAL doesn't!!! One must get close enough to the monitor to see > which axis has the focus, and fix it if its wrong before doing the touch > off. > I have accidentally touched off the wrong axis before, and I agree that it is very frustrating. But I don't blame the software. Sure, it might be _convenient_ for the touch-off dialog to default to whatever axis was moved last. But that is only a convenience. For example, suppose I'm trying to get a lathe tool touched off. I might use jogging or MDI to take a light cut, then jog (or MDI) the Z axis to get the tool clear _without_ moving X. Then I can get out the micrometer, measure the diameter I just cut, and touch off X accordingly. Note that I moved Z last but want to touch off X After accidentally touching off the wrong axis once or twice I learned that it is MY JOB to make sure I'm touching off the right axis. The software can't read my mind. Sure, I _often_ want to touch off the last axis I moved, but not _always_ -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] change of subject, brass or copper?
On Sun, Jul 16, 2017, at 02:51 AM, Gene Heskett wrote: (snip) > Some of this I should be > doing between centers, driving the workpiece with a dog, but I don't > have a 5C to MT2 adaptor. I might see if I can find one tomorrow. My bed > is calling me now. If you are referring to the headstock end, you don't need an adapter. Just chuck a piece of scrap steel in your 3-jaw and turn a 60 degree point on it. Doesn't matter how bad the 3-jaw is. If you turn the point in place and don't remove it until you are done with the job it WILL be centered. For the next job, stick it back in the chuck and just take enough of a skim cut to make sure it is centered again. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Multi-meter recommendations
On Thu, Jul 13, 2017, at 03:48 PM, Nicklas Karlsson wrote: > Fluke work great but are a little bit expensive. Unless accuracy is important > I guess any would do. Fluke is indeed expensive. However, I would change the last part to "Unless _safety_ is important I guess any would do". Cheap imported meters are often as accurate as brand-name meters costing 5-10 times as much. But one of the differences is the input protection. What happens if you accidently hook your meter probes across line voltage when it is set to measure current? Most meters, even cheap ones, have a fuse that will blow in that case. If you accidentally tried to measure a 24V power supply or even a 120V AC line while set for current, you'll probably be fine. If you accidentally tried to measure a 480V line with a Fluke, you'll still be fine - the fuse in a Fluke is rated 600V and has a high interrupting current rating. But the fuse in a cheap knock-off meter can't interrupt 480V fault current and is likely to explode in your hand trying. I have a Fluke and a cheap meter. On the bench when I'm working with low voltage I'll use whichever one is handy. Both are accurate, and the cheap one actually has a few features that are nicer then my (older) Fluke. But for anything higher than 120V, I only use the Fluke. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Reading config values with a realtime HAL module.
Kind of a kludge, but the streamer/ halstreamer system could do what you are describing. The component that wants to use the data would export a clock pin and one or more input pins. Each edge of the clock pin delivers a value (or set of values) from an external file. In this application, it would only be clocked during startup. Once the necessary data is transferred the streamer part (realtime) would sit idle, and the halstreamer part (user space) would terminate. http://linuxcnc.org/docs/html/man/man9/streamer.9.html http://linuxcnc.org/docs/html/man/man1/halstreamer.1.html On Tue, Jul 4, 2017, at 01:28 AM, Dave Caroline wrote: > For probe compensation batch reading would be far more useful than compiled > in, > then it becomes simple to read the compensation file for any stylus > you change too. > > Dave Caroline > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Reading config values with a realtime HAL module.
On Fri, Jun 30, 2017, at 05:46 PM, Les Newell wrote: > Is it possible for a real time HAL module to read config values from > disk? I guess I could do it the ugly way and have two modules, one in > user space to read the disk and pass values to the mealtime module. > > My lathe is pretty worn near the headstock so it tends to turn tapers > when working near the chuck. I want to write a kinematics module to > compensate for this taper, basically adding an offset to X depending on > the Z position. To do this I need to pass values to the kinematics > module in a similar way to leadscrew compensation. > > In the previous setup I had a simple kinematics-ish module just before X > PID but it was a hack and didn't work very well, with all of the values > hard coded. It also did ugly things when homing. > > Les How many points do you need? If 16 or less, check out the lincurve component http://linuxcnc.org/docs/html/man/man9/lincurve.9.html -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Backlash comp, does it follow sign of encoder (input) scale?
Screw error comp isn't really applicable, but you can do something similar in HAL. You want (if I understand correctly) a compensation value that applies a minor tweak to Z as X moves, right? You could use the lincurve HAL component to calculate the compensation amount and the offset component to apply it to the Z axis. http://linuxcnc.org/docs/html/man/man9/lincurve.9.html http://linuxcnc.org/docs/html/man/man9/offset.9.html On Fri, Jun 30, 2017, at 11:07 AM, Mark wrote: > On 06/30/2017 10:40 AM, Stuart Stevenson wrote: > > Backlash compensation will not move the orthogonal axes in reference to the > > compensated axis motion. > > If you are having length problems during the motion of the Z axis then comp > > could help. > > > > My file shows the bidirectional compensation of LinuxCNC. > > Okay, so not really applicable to my case then. Back to the drawing board. > > Mark > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] LCNC TED Talk style
And another: https://www.youtube.com/watch?v=nSbgQOF7OUU That video doesn't show the "behind the scenes" stuff, but the system is controlled by LinuxCNC running custom HAL files (no g-code, just joystick control and a PyVCP panel for homing, etc). On Wed, Jun 14, 2017, at 06:11 AM, andy pugh wrote: > On 14 June 2017 at 10:32, Sven Wesley <svenne.d...@gmail.com> wrote: > > > I'm thinking, I should have a few really awesome LinuxCNC videos running > > during the presentation > > > > This was one of the more unusual uses: > https://www.youtube.com/watch?v=pOdsvN9MSY8 > > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is designed > for the especial use of mechanical geniuses, daredevils and lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Question on thread geometry
How are you touching off (or otherwise determining the X tool offset for the insert)? For example, if you calculate the offset assuming a sharp-V geometry (the simplest case), but touch off with the actual tip of the insert (not sharp), the insert will be in deeper than LCNC thinks it is when you touch off. So it will cut deeper later. On Fri, Jun 2, 2017, at 02:14 PM, tom-...@bgp.nu wrote: > Ok, thanks for the responses. I found some thread gauge wires and with them > have determined that we are cutting too deep. This would cause the pointy > peaks and root, so the next question is why are we cutting too deep…? We > believe we are entering the correct value for K (thread depth) but I was > observing the DRO and Linuxcnc seems to be sending the cutter quite a bit > below where it should stop. > > I am going to get some more definitive info what is exactly happening, but I > am now wondering if there is a bug in the G76 cycle (causing it to cut deeper > than it should) or if it is something on my machine… > > -Tom > > > > On Jun 2, 2017, at 12:31 PM, Ed <ate...@mwt.net> wrote: > > > > On 06/02/2017 10:36 AM, tom-...@bgp.nu wrote: > >> There is a custom adjusting screw that I buy commercially and when I get > >> them the threads have a text-book geometry to them. That is, they have a > >> small flat top on the major diameter and small flat bottom at the minor > >> diameter or root. They are made to class 2 or perhaps even class 3. I > >> know that these screws I am getting commercially are made using single > >> point carbide insert tooling on a cnc lathe. > >> By the way, this seems to happen for nearly every thread I have cut on > >> the machine, but I haven’t cared as much in the past as the screws have > >> been for my own purposes, but this one will be used in a product sent to > >> customers. > > SNIP > > > > > >> > >> I am wondering if I am doing something wrong with the insert I am using or > >> what. Any thoughts? > >> > > Get an insert for that particular TPI, it will leave the proper flat on the > > top and bottom of the thread. > > > > Ed. > > > > > > -- > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Milling Aluminum.
On Fri, Apr 14, 2017, at 11:37 AM, John Kasunich wrote: > > > On Thu, Apr 13, 2017, at 08:59 PM, Jon Elson wrote: > > On 04/13/2017 12:44 PM, Todd Zuercher wrote: > > > > > > But I'm cutting out a 2ft x 3ft window. It would be silly to pocket fill > > > that entire thing. > > Yes, that is something I do all the time. I call it > > trepanning, and I have programs to do that, also. However, > > there's no way to avoid the first cut at each level being a > > full-width (plowing) cut, and that is the most difficult > > part of the job. > > Yes, there is a way, and he is doing it. > > That's what "trochoidal path" is all about. > > https://www.youtube.com/watch?v=Pkgw-w_AoOo Better video with explanation https://www.youtube.com/watch?v=S-DB2Vmr0qw -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Milling Aluminum.
On Thu, Apr 13, 2017, at 08:59 PM, Jon Elson wrote: > On 04/13/2017 12:44 PM, Todd Zuercher wrote: > > > > But I'm cutting out a 2ft x 3ft window. It would be silly to pocket fill > > that entire thing. > Yes, that is something I do all the time. I call it > trepanning, and I have programs to do that, also. However, > there's no way to avoid the first cut at each level being a > full-width (plowing) cut, and that is the most difficult > part of the job. Yes, there is a way, and he is doing it. That's what "trochoidal path" is all about. https://www.youtube.com/watch?v=Pkgw-w_AoOo -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] for PCW?
On Fri, Apr 7, 2017, at 11:53 AM, Jon Elson wrote: > On 04/07/2017 10:29 AM, Gene Heskett wrote: > > What I want, but don't know if I can get, is to have the > > servo thread running at the highest priority, fully > > capable of interrupting the jog-thread, but the jog-thread > > cannot interrupt the servo thread as its not that time > > critical. How best to do that, given the tools available? > > Thanks Peter and everybody. Cheers, Gene Heskett > Faster threads will, in theory, interrupt slower threads. > But, the way RTAPI threads are set up, at least with RTAI, > the slower threads will be forced to run at multiples of the > faster thread period. Therefore, I think, the slower threads > will actually never get interrupted. I think they will just > get tacked onto the end after the faster thread runs. > Slower threads can get interrupted, if they take a long time to complete. Suppose you have a 1mS servo thread that takes 170uS to run. And a 10mS "jog thread" to use Gene's example, that takes 1300uS to run. starting at time 0, the servo thread will run it will finish at 170uS, then the jog thread will start at 1000uS, the servo thread will interrupt the jog thread, even though the jog thread has only run for 830uS and still has 470uS of work to do the servo thread will take its 170uS, and finish at 1170uS the jog thread will resume where it left off, and run for another 470uS, finishing its work at 1640uS non-realtime code will run from 1640uS to 2000uS at 2000uS, the servo thread will run for 170uS non-realtime code will run from 2170uS to 3000uS and so on, until 1uS, when the process repeats If a slow thread has lots to do, it can and will be interrupted by faster threads. Thread priority in HAL is automatically set up with the fastest threads having the highest priority so they can interrupt slower threads. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cast Bracket for FHA-25 Harmonic Actuator.
On Wed, Apr 5, 2017, at 05:02 AM, andy pugh wrote: > On 5 April 2017 at 03:29, Ralph Stirling <ralph.stirl...@wallawalla.edu> > wrote: > > I just wish there was an open source CAM tool of equal sophistication > > for CNC work... > > Unfortunately Autodesk have rather taken the wind out of the sails of > the open-source CAD / CAM projects. > Fusion 360 (Windows and Mac only) is (at the moment) zero cost to > hobbyists and offers very good CAD and excellent CAM. > > I can't help expecting Autodesk to wait until everyone is committed to > their offering then "turning evil" and starting to charge. > I've been thinking the same thing... I'm trying to decide what to do for my 3D CAD work. I first got exposed to modern CAD when I was using Inventor at work. Did some home projects using my work laptop and Inventor license, love the power of the tool. But my work priorities have changed and I no longer have access to Inventor. Which really drives home the problems of these tools. The data is NOT portable. I have a couple years of part-time hobby work that I simply can't recover. Solidworks seems to be the industry standard (something like 60% market share), but the pricing puts it just as far out of reach as Inventor or Pro-E. I actually bought a licence for Alibre a couple years ago for almost $1K, but I very quickly became unhappy with both the tool and the company (especially the company). Not willing to invest further work into stuff that will be trapped in their format. That leaves Fusion 360 and FreeCAD. I certainly like the philosophy behind FreeCAD. Unfortunately, my projects are typically machinery, and I absolutely need to make assemblies from a mix of standard (screws, bearings, etc) and custom (housings, shafts, etc) parts. Assemblies seem to be a distant after- thought for FreeCAD. There have been several attempts at an "assembly workbench" for FreeCAD, and it looks like every one has died before becoming usable. I think part of the problem might be that the core of FreeCAD was designed by people who were thinking only of part design instead of complete machine design. I haven't had time to actually set up and use FreeCAD, if anyone can comment on how it handles assemblies I'd like to hear from you. Fusion 360 seems like a very nice tool... but like Andy, I don't trust Autodesk for a second. My hobby projects move slowly - I need tools that are viable over a timescale of a decade or more, (or data format that let me extract my work and move to another tool). I just don't see that in the 3D world, from anyone. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Milling setup question
Yet another possibility: two pieces of matched diameter stock somewhere between 25-50mm diameter (non-critical) and 25-75mm long. Non-critical hole down the center of each one to fit a clamping stud. Put two t-nuts in the center t-slot, bolt one cylinder down using one of the nuts in a arbitrary location. Set the part over the cylinder, insert the second cylinder and slide them apart until the two cylinders are touching the inside of your big bore at the left and right sides. Tighten down the second cylinder. Carefully lift the part up and off. The gap between the cylinders is centered on the big bore. Use the coaxial indicator (spindle off, rotate manually) to center the spindle in the gap. Lock X. Replace part, indicate base perpendicular to spindle, clamp down. On Thu, Mar 30, 2017, at 09:00 AM, andy pugh wrote: > On 30 March 2017 at 13:41, Cristian Bontas <cristianbonta...@gmail.com> wrote: > > You could turn a cylinder that fits snugly in the large hole. > > Certainly a possibility, but at 120mm quite a big chunk of material to > use just as a jig. > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Milling setup question
Elaborating on my own post: On Thu, Mar 30, 2017, at 03:21 PM, John Kasunich wrote: > Why can't it be as 120mm diameter x 5mm thick disk? Turn said disk on the lathe, and bore a concentric but much smaller hole in the center. Then you can indicate to either the hole or a dowel inserted in the hole. There would be at least two, maybe four, other holes, non-critical, for bolting the disk down to the table. Bolt it down loosely with the table empty, indicate such that spindle points thru the center of the vertical dowel, tighten bolts and check again. Then set the part over the disk, indicate base perpendicular to spindle, and clamp part down. > On Thu, Mar 30, 2017, at 09:00 AM, andy pugh wrote: > > On 30 March 2017 at 13:41, Cristian Bontas <cristianbonta...@gmail.com> > > wrote: > > > You could turn a cylinder that fits snugly in the large hole. > > > > Certainly a possibility, but at 120mm quite a big chunk of material to > > use just as a jig. > > > > -- > > atp > > "A motorcycle is a bicycle with a pandemonium attachment and is > > designed for the especial use of mechanical geniuses, daredevils and > > lunatics." > > — George Fitch, Atlanta Constitution Newspaper, 1916 > > > > -- > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > -- > John Kasunich > jmkasun...@fastmail.fm -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Milling setup question
Why can't it be as 120mm diameter x 5mm thick disk? On Thu, Mar 30, 2017, at 09:00 AM, andy pugh wrote: > On 30 March 2017 at 13:41, Cristian Bontas <cristianbonta...@gmail.com> wrote: > > You could turn a cylinder that fits snugly in the large hole. > > Certainly a possibility, but at 120mm quite a big chunk of material to > use just as a jig. > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Documentaion Question / Addition
There was a time (in the late 1990's to early 2000's) when LinuxCNC (EMC back then) had three realtime threads. What we now know as the base and servo threads, and a third slower thread for the trajectory planner. Back in the day, computers couldn't necessarily do all the trajectory planner (and especially kinematics) math quick enough, so the planner ran at 1/10 the rate and the output was interpolated at the servo rate. The third thread went away in 2004 or so when EMC2 rewrote much of the motion controller. There is no mechanism for detecting unused ini file parameters, so it is quite possible that no code has actually used the parameters you mention in more than a decade. I'm not in a position to do it, but I wonder how hard it would be to grep thru the code to see if those parameters are used? If they're not, they should be deleted from the sample configs. John Kasunich On Wed, Mar 29, 2017, at 05:34 PM, Joe Hildreth wrote: > It's me again ... :-) > > While in the [TRAJ] section of the INI file is see the variable CYCLE_TIME = > 0.010, but is not mentioned in the INI config documents. I am only guessing > that this is the polling interval time for the trajectory planner but am not > sure. Can I add this to my list? > > Thanks again, sorry to be a pain. > > Joe Hildreth > > - On Mar 29, 2017, at 3:35 PM, Joe Hildreth j...@threerivershospital.com > wrote: > > > Hello all, > > > > I am going through the INI file of my stepper based Gantry machine and am > > looking at the [EMCMOT] section. In this section I see two variables: > > > > COMM_TIMEOUT = 1.0 > > COMM_WAIT = 0.010 > > > > I am guessing they have something to do with the communication times, but > > the > > INI Configuration section of the documentation does not mention these, and I > > see no reference to them in the core component motion section of the > > documentation. > > > > Can someone explain these to me and maybe add them to the INI config docs? > > > > Many thanks for your help, patience and time. > > > > Joe Hildreth > > -- > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Making taper lock hubs
I can't see how lathe alignment could affect your angle. If you turned the OD running forwards with the cutting tool in front and bored the ID running in reverse with the cutting tool in back, then yes. But if both were done with the spindle going forward then the tip of the cutting tool is in exactly the same place and should be moving at exactly the same angle. I must say that if I was doing this I probably would program both the ID and OD tapers _exactly_ the same, even if that means one of them is longer than necessary and wastes a bit of time cutting air. When you change the Z length you leave room for errors to creep in. I suspect that delta-x divided by delta-z is not the same in your ID program vs. your OD program. On Tue, Mar 28, 2017, at 09:54 AM, Gene Heskett wrote: > On Monday 27 March 2017 03:56:53 Gene Heskett wrote: > > > On Monday 27 March 2017 00:17:19 Erik Christiansen wrote: > > > On 26.03.17 18:53, Gene Heskett wrote: > > > > But is 7 the correct factor? It should be fairly easy to jack it > > > > back out. > > > > > > Gene, I've never made one of them, but looking here: > > > > > > http://www.google.com.au/url?sa=t=j==s=web=8 > > >d= > > > 0ahUKEwiE6q-q5PXSAhWGKWMKHeZIAf0QFgg-MAc=http%3A%2F%2Funiversalb > > >ear > > > ings.com.au%2Fdownload-subproducts%2Ftaperlock-bushes=AFQjCNGOFI > > >vAU jPQ1JccxaHkdEjC0hT5oA > > > > > > the first bush in the table seems to be: > > > > > > atan((35.2 - 33.7)/11.1) = 7.7° included, near as dammit. > > > So I did the taper turn at TAN[7.7]*total z len which was 0.735" > > Finished (except for jacking holes) hub looks great. Set it aside for > now. > > Chuck pulley and hammer around for concentricity etc, spins good and > true. Edit code to do the tapered bore, but change for a full inch of Z > motion, so I used the TAN[7.7] raw as the inner factor to sub from the > bore at z left end. Using one of those cheap $20 a kit of cemented > carbide boring bars. Re-shapened with a diamond disk in a dremel. Get it > bored big enough (and bore looks like shit, tool is skipping) to start > checking fit using the hub I just made at what was supposed to be the > same angle. Bored angle too steep by quite a bit. Hub goes in about > half way, jams on tip of hub and can be rocked around. Its not trashed > yet, but this is where I start fiddling with bar sharpening angles, > widening the hole at the deep end until it fits. And changing the bar to > a monster I made years ago, a 5/8" diameter bar about 10" long I had > made a groove in the side of to hold a small bar that seriously needed > some stiffening. Takes std diamond pattern chips. Then gradually reduce > the x decrement until it fits. > > I don't believe the spindle head on this lathe has ever aligned with the > z motion of the carriage. I replaced the whole head a year ago after > refitting a new head with all metal gears, and while I cleaned the paint > overspray off the mating surfaces on its bottom, I think this one is > sitting even more out of alignment. At one time years ago I had wasted a > piece of cold roll and a few days adding an offset per inch factor to x > until it was turning a decent cylinder, and should have painted it on > the monitor, as its in the area of 7 thou per inch, but that was on the > OEM head assembly. Cheap, mumble mumble, Chinese crap. > > Andway, change the bar to the big boy, then start shaving the angle is > todays project. After I go to the store and get stuff for breakfast and > fix it for us. > > > Cheers, Gene Heskett > > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Thing with a square hole.
You could mill a 10mm wide x 5mm deep slot in two rectangular bars, then silver-braze them together. Might not be strong enough, depends on if the OD is big enough to leave a reasonable joint area. Welding would probably leave a hardened zone and be miserable to machine afterwards. John On Mon, Mar 20, 2017, at 09:58 AM, andy pugh wrote: > I want to make some D1-4 cams for a 4th-axis project. > These need a 10mm square hole (but 3/8 would be fine too). > I don't think I can polygon-bore a square, it needs too much > tool-relief. (I guess I should try, though). > > If I could find something like a 3/8" drive socket with no hole in it > that would be a good starting point. Any ideas? > > I have thought of having a hex hole and starting from an M24 grub > screw (setscrew). But those cost about the same as an actual cam. > (though the only source of cams I have found in the UK have no stock, > or I would have bought them). > http://spares.xyzmachinetools.com/XYZ-TRAINER-1330-1340/products/29/ > lists zero stock at £7.77 > > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Suggestions wanted - how to control robot
On Thu, Mar 16, 2017, at 10:40 AM, Andy Evans wrote: > > We are thinking that we need a small industrial robot (Mitsubishi, > Fanuc) with .002" or so accuracy. The fixture will do some > self-aligning of the part as it is clamped. Does anyone have any > recommendations and sources for a suitable robot? > For any robot, four key parameters are: 1) Size (and especially weight) of the part you are picking up. Are you engraving 1" square x 0.020" thick aluminum nameplates, or boring cylinders in cast iron engine blocks? 2) Degrees of freedom. If the magazine is lined up with the fixture, you could probably use only Z (pick up, put down), X (move between magazine and fixture) and A or B (flip part). Some sort of simple Cartesian slides could work. On the other hand, if you use a puma type robot with waist, shoulder and elbow, you might need 2-3 additional degrees at the wrist to keep the part in the proper orientation. 3) Size of the work envelope. Can the magazine be two inches from the fixture? Or is it several feet away? 4) Precision/accuracy. That is the only one of the four that you actually specified. Small workspaces with light workpieces and fewer degrees of freedom can be 1/10 or even 1/100 the price of large workspaces with heavy workpieces and many degrees of freedom. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] jogging again
On Tue, Mar 14, 2017, at 10:56 AM, Gene Heskett wrote: > Greetings all; > > I threw out quite a few lines of code, but while its now working, its > working at 4x the movement I am asking it for. > > I am now sending my distance increment to the axis.x.scale and > joint.0.scale inputs. > > and sending the hm2...encoder.count to axis.x.counts and joint.0.counts > > It seems that regardless of what I > setp hm2_[HOSTMOT2](BOARD).0.encoder.01.scale at,from 1 to 16 tested, one > click is a count of 4 at the count output. So I am getting 4x the > movement I want. So sending a .0002", gets me .0008" rad change > and .0016" dia change. > > Is there a fix for this unwanted 4 per click? Or am I getting a 4x > multiplier because I am feeding both axis and joint the encoder count? > > Thanks all; > > Cheers, Gene Heskett > -- The jog scale inputs are "distance you want to travel per jogwheel count". Your wheel sends four counts for one detent. If you want one detent to be 0.001" set jog-scale to 1/4 of that, 0.00025". If you want one detent to be 0.010", set jog-scale to 0.0025". And so on... hm2_[HOSTMOT2](BOARD).0.encoder.01.scale has nothing to do with it. That is used INSIDE the encoder driver to scale the floating point output of the encoder. Wheel jogging doesn't use the floating point output of the encoder, it uses the raw counts. The reason for that is so that you can change the jog-scale any time you want. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] damn radio shack
On Tue, Mar 7, 2017, at 04:41 AM, Gene Heskett wrote: > the 1/8" bit was walking out of the collet because those TTS > holders aren't keyed, so they slip and limit the torque I can apply when > tightening the collet nut. If those are the holders I think they are, there should be two flats on the body. The intent is that you use two wrenches, on one the body flats and one on the collet nut. -- John Kasunich jmkasun...@fastmail.fm -- Announcing the Oxford Dictionaries API! The API offers world-renowned dictionary content that is easy and intuitive to access. Sign up for an account today to start using our lexical data to power your apps and projects. Get started today and enter our developer competition. http://sdm.link/oxford ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] MPG detents
On Wed, Mar 1, 2017, at 07:42 AM, Roland Jollivet wrote: > I had always assumed that machine MPG's generated one state change per > click, but following Gene's discussion, I pulled out my 1988 Fanuc MPG, and > saw that it was also 4-states per click. Obviously, one 'pulse'/detent > > Does anyone know the rationale behind this? > I assumed one always wants one step per click, so why not use a 25ppr > encoder and use every change? > Used as currently is, it would have to be a software /4 to be useful. You > could also do a /2 or /1, but no-one ever wants a x2 or x4 on their MPG > It's always x10, x100 or whatever, so the count/detent would always have to > be n/4 x 1 .. or.. n/4 x10 in software. > > Alternatively, if I was going to make my own MPG, surely I would just make > a 25ppr encoder and make it 1 detent/change? > It's far easier for me to make, so surely it would have been for Fanuc too? > > What am I missing? > Smoothness of movement is 4x better with the finer resolution. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] encoder Q too
What do you want to use the direction for? If you are using the jogwheel as a jogwheel, you don't need direction at all. LinuxCNC's motion module handles that. On Sat, Feb 25, 2017, at 04:39 PM, Gene Heskett wrote: > Greetings all; > > I note the encoder module does not specifically have a "direction" > output. Is it sufficient to run the velocity thru a wcomp, compare to > 0., and use the over/under pins for multiswitche's direction to > count? Seems like it ought to work so I'll hack up some more hal code. > That will need an and2 to gate it of course to when the button is > pushed. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How do I enable the 2-pass processing of the hal file(s)
On Tue, Dec 13, 2016, at 11:08 AM, Gene Heskett wrote: > On Tuesday 13 December 2016 09:27:22 John Kasunich wrote: > That doesn't sound nearly so usefull John, except as a way to fix a > screwup in an existing config. By what you say, I can't even do a > addf mux2 1 > as the first addf it encounters. > > I'd imagine there was a theory back when though. > The reason the "position" option was added to addf was for interactive work, where you are literally building a HAL on the fly from the command line. If you have a hal file, you should just use your text editor to put the addf lines in the proper order. If you are doing it on the fly from the command line and realize that some function needs to be early in the thread, the position is the only way to do that short of starting over. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How do I enable the 2-pass processing of the hal file(s)
On Tue, Dec 13, 2016, at 06:52 AM, Gene Heskett wrote:
> On Tuesday 13 December 2016 04:35:44 andy pugh wrote:
> > Note that you can specify a thread position explicitly in the "addf"
> > command. I can't find it mentioned in the docs, but it is there in the
> > code
> > https://github.com/LinuxCNC/linuxcnc/blob/af15a4d90e1d51d5309db65fe1c9
> >511e486df411/src/hal/hal_lib.c#L1973
Oops, looks like that got left out of the man page. It has been in the code
pretty much forever, and is documented in halcmd's built-in help, like so:
} else if (strcmp(command, "addf") == 0) {
printf("addf functname threadname [position]\n");
printf(" Adds function 'functname' to thread 'threadname'. If\n");
printf(" 'position' is specified, adds the function to that spot\n");
printf(" in the thread, otherwise adds it to the end. Negative\n");
printf(" 'position' means position with respect to the end of the\n");
printf(" thread. For example '1' is start of thread, '-1' is the\n");
printf(" end of the thread, '-3' is third from the end.\n");
> I'd have to assume its a space/tab separated argument, from the code,
> last in the string before any # identifying comments. And it opens the
> door to even greater freedom in composing a .hal sequence of files in
> the manner I described & you clipped. Planning ahead, I'll try to use
> blocks of numbers that may leave gaps so there is room to go back later
> and insert the gear change suggesting code in the intervening, still
> unused numerical space in the thread execution order. I currently have
> 78 in TLM's main hal file, so as a starter I'll use 1-20 for one
> function, 21-40 for the next group. Wash rinse and repeat. And find out
> if it doesn't like missing numbers in the sequence.
It doesn't work that way.
The position is relative to the function list AS IT EXISTS at the moment
the addf command is executed. Functions are stored in a simple linked
list, not an array, so the concept of "empty spaces" doesn't exist. Think
of index cards in a card file. You can insert a new card between the 3rd
and 4th cards. When you do, the old 4th card becomes the 5th card, and
the new card becomes the 4th one. There are no numbers associated
with the cards - if you want to know which one is the 4th, you just start
at the front of the list and count. If you want to know which one is 3rd
from the end you start at the end and count the other way.
If you have 5 functions in a thread at the moment you run an addf
command, the only legal values for "position" are -6 thru 6. Positive
6 means 6th in the thread, so it counts off five from the front of the
list and inserts the new one after #5. If you tried positive 7 it would
need to count off 6 from the front of the list. There are only 5, so the
counting would hit the end of the list and throw an error message.
--
John Kasunich
jmkasun...@fastmail.fm
--
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Re: [Emc-users] An observation on digital calipers
On Mon, Oct 31, 2016, at 02:42 PM, John Kasunich wrote: > > This picture is under 50K, hopefully nobody minds. LOL, apparently the list software minds, and stripped it out. http://www.shars.com/media/catalog/product/cache/1/image/540x/17f82f742ffe127f42dca9de82fb58b1/3/0/303-1340b.jpg -- John Kasunich jmkasun...@fastmail.fm -- Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] An observation on digital calipers
On Mon, Oct 31, 2016, at 02:37 PM, John Kasunich wrote: > > > On Mon, Oct 31, 2016, at 01:15 PM, Gene Heskett wrote: > > On Monday 31 October 2016 10:44:33 John Kasunich wrote: > > > > That's why I don't own a digital caliper. Mine all have dials > > > > > > I even have a couple (one at work, one at home) 6" dual-needle > > > dial > > > calipers that read in metric and inches. > > > > Now thats getting seriously kewl John. :) But I'd also bet they > > weren't > > cheap. :( > > > > Actually they were under $30. Shars brand, china made. But they > work fine. > http://www.shars.com/products/measuring/caliper/6-dual-reading-inch-metric-dial-caliper > This picture is under 50K, hopefully nobody minds. It is reading 0.298" and 7.57mm -- John Kasunich jmkasun...@fastmail.fm -- Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] An observation on digital calipers
On Mon, Oct 31, 2016, at 01:15 PM, Gene Heskett wrote: > On Monday 31 October 2016 10:44:33 John Kasunich wrote: > > That's why I don't own a digital caliper. Mine all have dials > > > > I even have a couple (one at work, one at home) 6" dual-needle dial > > calipers that read in metric and inches. > > Now thats getting seriously kewl John. :) But I'd also bet they weren't > cheap. :( > Actually they were under $30. Shars brand, china made. But they work fine. http://www.shars.com/products/measuring/caliper/6-dual-reading-inch-metric-dial-caliper One thing I learned from experience - if you drop them and the pinion jumps a tooth on the rack, you aren't going to be able to get both needles pointing at zero again by disengaging and re-engaging the pinion. It seems like it can go together a thousand ways and only one way has both needles aligned. I took off the bezel, carefully popped off both needles, and pressed them back on in the proper orientation. -- John Kasunich jmkasun...@fastmail.fm -- Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] An observation on digital calipers
On Mon, Oct 31, 2016, at 07:28 AM, andy pugh wrote: > My little digital caliper is playing up. It could just be a low > battery, it has been flashing the LCD for at least a year. > (As an aside, why do they run normally for about a week then flash the > display for about a year?) > Anyway, moving the slider very slowly it goes from 0.3995" straight to > 1.200", then acts a bit random until it switches from 1,499 to a > (correct) 0.800" That's why I don't own a digital caliper. Mine all have dials (except the 36" Starrett vernier) and I've never had a dead battery in 17 years. I even have a couple (one at work, one at home) 6" dual-needle dial calipers that read in metric and inches. -- John Kasunich jmkasun...@fastmail.fm -- The Command Line: Reinvented for Modern Developers Did the resurgence of CLI tooling catch you by surprise? Reconnect with the command line and become more productive. Learn the new .NET and ASP.NET CLI. Get your free copy! http://sdm.link/telerik ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Machinekit? --> NML --> Horrible procedures
I think Nicklas might be referring to this: http://www.machinekit.io/community/c4/ It's a formal sounding document On Mon, Oct 24, 2016, at 12:19 PM, Chris Albertson wrote: > On Mon, Oct 24, 2016 at 8:37 AM, Nicklas Karlsson > <nicklas.karlsso...@gmail.com> wrote: > " ... horrible procedures for developers ..." > > Hard to answer your question as it depends on what you think of as > being "horrible".Can you be specific? > > They are using Git and do have some rules like your code has to > compile, pass self tests and you need to supply an explanation of what > it does and so on. very basic stuff like that. > > > -- > > Chris Albertson > Redondo Beach, California > > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Machinekit?
On Wed, Oct 19, 2016, at 01:55 PM, andy pugh wrote: > On 19 October 2016 at 18:39, <dan...@austin.rr.com> wrote: > > > Anybody familiar with this? > > Somewhat. Machinekit is a fork of LinuxCNC, so many things are exactly > the same. The split was a few years ago now, so there has been some > divergence, but they probbaly look very similar indeed to a user. > I looked into machinekit because I wanted to use a BeagelBone. I found the user-level documentation to be disappointing. Things that are the same in machinekit and LinuxCNC inherited the good LinuxCNC documentation. I can't say enough good things about what John Thornton (and others) have done for our documentation. Unfortunately things that are new in machinekit (and thus the reason I wanted to use it) are barely documented at all. Recently Jeff Epler and others have figured out how to build LinuxCNC for beaglebone, so I came back to my roots and am happy. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Wat OT: Question about injection molding of PVC
Injection pressure will be trying to force the two sides of your mold apart. That's why injection molds are made of tool steel, and injection machines have VERY sturdy construction to hold the mold closed. I saw a machine that might be big enough to make your parts - the mold closing cylinder was about 2 feet (0.6m) in diameter, and the four steel tie-rods that held the machine together against the clamp force were about 100mm diameter. Could you make it out of four strips with some kind of joining at the corners? John Kasunich On Sat, Oct 15, 2016, at 08:12 PM, Leonardo Marsaglia wrote: > Hello to all. > > I'm sure here I'm going to find good answers so I decided to start from > here. > > I'm planning to do some thermoforming production work but the sheet plastic > I need to use is rectangular with a rectangular hole in the middle (I > attached a picture so you can see). So to use regular PVC sheet would imply > a lot of waste. > > I came up with the idea of injecting the PVC using a manual clamped mould > and injecting it with a screw driven piston. The difficult part comes here, > I need to inject almost 3 kg of PVC. The moulds are going to be pretty > simple as you can see but I would like to know if there's any good source > to determine the approximate power I would need to drive the screw that > moves the piston. > > There's the possibility of using two pistons one on each side to make > things easier. Off course I would need to reduce the motors with worm and > gear and then connect the gear to the screw that drives the piston. But my > main concern is if this approach is correct or if I should forget about it. > > I didn't even consider the hydraulic pump because the cost would be a lot. > Also take into account that I'm not intending to make lots of these > injections per hour, so injection times could be slower than the industry > standard. > > I hope I've been clear about my doubts and I would be thankful if you can > point me to any source of info about this, or help me to be more sure about > the dimensions of what I need to do. > > Thanks as always! > > -- > *Leonardo Marsaglia*. > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Email had 1 attachment: > + shape.png > 360k (image/png) -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] One other Q related to the bellows fittings
On Sun, Oct 9, 2016, at 12:07 PM, MC Cason wrote: >If you still intend to use positive pressure, an aquarium pump with a > small check valve, would be a easier, cheaper, and quieter, alternative > to a tire air compressor. It would also use an ordinary wall plug, > instead of using more power off of your power supply. This seems like the most reasonable solution yet, other than the simple bypass around the nut. The rest seems like killing ants with sledgehammers. -- John Kasunich jmkasun...@fastmail.fm -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Best way to jog all three axis using a single push button?
On Thu, Sep 29, 2016, at 11:15 AM, John Kasunich wrote: > > > On Thu, Sep 29, 2016, at 10:48 AM, Florian Rist wrote: > > Could I do something with the axis jog pins: > > > > axis.0.jog-vel-mode > > axis.0.jog-enable > > axis.0.jog-scale > > Those are for using a jogwheel. See > http://linuxcnc.org/docs/2.7/html/config/core-components.html > > You could use a stepgen in quadrature mode to fake the jogwheel > counts, and use two buttons to make that stepgen go up or down. > If you send the "jogwheel" counts to all axes, set the axis.N.jog-scale > the same for all axes, and turn on axis.N.jog-enable for all axes, > they WILL move the same distance. Actually you don't even have to mess around with the stepgen. All you need is an S32 signal that can be increment or decremented. The updown component can generate such a signal. It requires pulses on its up or down input pins to count. To make pulses from a pushbutton you could use a pair of xor2 components. (One for up, one for down). Connect the button to one of the XOR inputs. Connect the XOR output to its other input (feedback). When the button signal is "1", the output will toggle every servo period - meaning 500 counts per second if using a 1mS servo thread. When the button signal is "0" the output will sit still. If you know that the updown block will be counting up or down at 500Hz, you can set axis.N.jog-scale to get whatever speed you want at the motor. For example, a scale of 0.01" per tick times 500 ticks per second would be 5 inches per second. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Best way to jog all three axis using a single push button?
On Thu, Sep 29, 2016, at 10:48 AM, Florian Rist wrote: > Hi John > > > Do you need/intend to use g-code at all for this installation? > > Yes. In that case you want the LinuxCNC motion planner. It will handle all the jogging, homing, etc, for you. > > And I'm now just trying to modify it quickly to do a manual > demonstration. > > Could I do something with the axis jog pins: > > axis.0.jog-vel-mode > axis.0.jog-enable > axis.0.jog-scale Those are for using a jogwheel. See http://linuxcnc.org/docs/2.7/html/config/core-components.html I just read that using halui didn't work because the axes don't track perfectly (not really a surprise, since halui is a non-realtime component). You could use a stepgen in quadrature mode to fake the jogwheel counts, and use two buttons to make that stepgen go up or down. If you send the "jogwheel" counts to all axes, set the axis.N.jog-scale the same for all axes, and turn on axis.N.jog-enable for all axes, they WILL move the same distance. > > I have a few custom HAL components that I could share if useful. > > For example, one lets you switch from manually controlling each > > motor (for "homing") to coordinated control. > > Oh, sounds very interesting. As long as you are using LinuxCNC's motion controller and g-code you don't need my components. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Best way to jog all three axis using a single push button?
Do you need/intend to use g-code at all for this installation? If not, it is probably a good candidate for a "hal-only" configuration. Stepgens, limit2 or limit3 blocks, muxes, integrators, etc, can be used to do just about anything you can imagine. PyVCP can be used for on-screen controls, and joysticks, buttons or other devices for external controls. As an example: http://www.teslaorchestra.com/claw-game.html I have a few custom HAL components that I could share if useful. For example, one lets you switch from manually controlling each motor (for "homing") to coordinated control. On Thu, Sep 29, 2016, at 09:58 AM, Florian Rist wrote: > Hi, > just a simple question: > > I need to add two momentary switches to a 3 axis machine (not a mill, > more like a art installation) that jog all axis (xyz). Press one button > all axis move up, press the other one all move done in sync. > > Whats the best way to do this. The three axis are moved by servo motors > via a Mesa card and Mesa amplifiers. > > I have plenty of unused IOs on the Mesa card. > -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] output sink of the 667 hall effect?
On Tue, Sep 13, 2016, at 06:51 AM, Gene Heskett wrote: > On Tuesday 13 September 2016 04:13:15 andy pugh wrote: > > > ethernet-blue-data-cable-4x2x0-12mm-od-6-3mm-49-1790 > > 5 bucks a meter? A week to ship ARO? They obviously aren't "hungry". > Based on buying some cutting tools from a limey vendor a year ago, I'll > be 6 weeks getting it into my hands. Nyet. Andy posts UK based suppliers because he is in the UK. The point is that the stuff is out there, and there is probably a US seller if you use the right search terms. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] IMTS Chicago
Let me know when you expect to be doing the HGR run. Not sure if I can get off work, but I'll try. (I live 20 minutes from HGR.) On Mon, Sep 12, 2016, at 10:12 AM, Stuart Stevenson wrote: > Standing here ready to go in and wondering if anyone on the list is here > today. > Am planning an HGR run tomorrow. > Kim K. is here with me. > Would like to meet up with any LinuxCNC users here. > Thanks > -- > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohodev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Need unlocked copy of a pdf for a breakout board I just bought two of.
Chris Albertson [albertson.ch...@gmail.com] wrote: > > The other question: So we get the source code VHDL files for the firmware > inside this card? This means we could use any FPGA card or even build one > from a FPGA chip > Ralph Stirling replied: > > Yes, Mesa has been kind enough to open-source all the vhdl for their cards. > > Mesa has made a tremendous contribution to the community with their > hardware and firmware. > Indeed. And for that reason alone I would buy the Mesa FPGA cards, even if someone else was cheaper. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] "Probe triggered during jog"
On Wed, Sep 7, 2016, at 02:43 AM, Danny Miller wrote: > I have a wireless toolsetting probe here. It's nice, but it's naturally > sensitive. Even when you're not using it, very easy to trip, and > LinuxCNC generates a "Probe triggering during jog" error. Just bump the > table. The probe doesn't even have a physical hard switch, just the plate. > > Hmm. I don't know why it was coded to do this, but it's a problem. > Basically it should be ignoring Probe-in if it's not probing. You wouldn't think that if you ever ran the business end of a $500 probe into the side of a vise while jogging The normal behavior is to protect sensitive and expensive equipment. If you don't like that, you can modify it using HAL logic quite easily. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spurious edge on startup
On Mon, Sep 5, 2016, at 05:39 PM, Danny Miller wrote: > I have a HAL which is detecting a false edge when loading LinuxCNC. > > I have AM882 drives which have an Alarm signal output, and an Enable > signal input. Alarm is active-low, Enable is active by default unless > LinuxCNC deasserts it, all goes through a 7i92 card. The Alarm signal > is tied to its automatic stall detection. If tripped, it disables the > STEP input, and only cycling Enable pin resets the drive. The Enable > pin also disables the motor current output entirely, which is > undesirable, the Z will drop. Initially I had Enable go inactive during > estop but it caused the Z to fall for no good reason. Arguably less > safe. You have an emergency, bit is spinning, you hit e-stop, the Z > falls with the motor still going. Is this a retrofit of a professional class machine? Or a hobby class machine? I can't imagine a pro-class CNC machine that will drop the Z. If the screw doesn't have enough friction to hold the Z, they will put a spring-applied, electrically released brake on the Z servo motor. ANYTHING that causes loss of servo control (estop, power failure, axis disable, following error) kills power to the brake coil and the springs apply the brake (fail-safe). If your machine has a free-falling Z and doesn't have a brake, sooner or later there is going to be an accident. What happens in a power failure? I strongly recommend either mechanically or pneumatically counterbalancing the Z, or adding a fail-safe brake to the motor. > I just simplified it in HAL as "if the estop-assert AND Alarm-assert > have a posedge, trigger a one-shot to deassert the Enable signal for > 0.25 sec". > > It mostly does what I expect! However, when I boot up LinuxCNC, Enable > deasserts for 0.25 sec and the Z falls a bit, I definitely don't want it > to do that without Alarm being asserted. At the time, the drivers were > already physically powered and Alarm is NOT asserted (low) for sure. > > I presume the first servo-thread cycle has a glitchy value on startup, > probably the 7i92 itself. I'm not sure what actually does that, the > one-shot has to have a posedge to start the one-shot, not a level. If > the HAL saw Alarm pin as low (asserted) during booting and the first > cycle of servo-thread saw its correct value (high, deasserted), that > should NOT trigger the one-shot. Wrong edge. > > Any idea? > Not sure of the specifics of your case. But in general you cannot trust ANY bit coming from a computer to ALWAYS be right. All bets are off before LinuxCNC runs, during startup, and after LinuxCNC exits. For example, I have a PC that toggles the parport bits several times during boot. It can be a bit disconcerting hearing the spindle motor reversing contactor thunking in and out. But nothing bad happens, because the main power going to that contactor goes thru another contactor that has a charge-pump based HARDWARE estop. That main power contactor doesn't pull in until LinuxCNC is started and I bring it out of estop. And the main power contactor drops back out as soon as LinuxCNC stops. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] What does "CNC" really mean?
Just buy the insurance... Only 1.6 million anyway (I saw 512GB microSD advertised for $60 each) Actually, ought to be less than that - you should be able to negotiate a quantity discount. On Fri, Sep 2, 2016, at 02:24 PM, Andy Pugh wrote: > > > > On 2 Sep 2016, at 21:14, John Kasunich <jmkasun...@fastmail.fm> wrote: > > > > A shoebox (4" x 6" x 12") can hold 27,000 microSD cards > > If you trust Fedex to not lose your $10,000,000 > > > -- > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] What does "CNC" really mean?
On Fri, Sep 2, 2016, at 01:32 PM, Dave Cole wrote: > Yet it is hardly a blip on an $8 - 32 gig stick drive. The old > days of 360K floppies and those newfangled hi-capacity 720 K and 1.44 > meg floppies seem so long ago You could stick a 1.44 meg floppy > in your pocket! That was crazy! Reminds me of an old saying. "Never underestimate the bandwidth of a station wagon full of tapes rolling down the highway at 60MPH." The modern version would be a shoebox full of microSD cards in a FedEx plane. You can buy 512GB microSD cards. They are 11x15x1mm. A shoebox (4" x 6" x 12") can hold 27,000 microSD cards. That is 13.8 petabytes (peta = 10^15). FedEx can deliver it just about anywhere in 24 hours. That works out to 160 giga-bytes per second, or about 1200 channels of gigabit Ethernet Of course there is the small problem of reading the data off the cards when it arrives. -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] What does "CNC" really mean?
On Fri, Sep 2, 2016, at 01:34 PM, Ken Strauss wrote: > Is that using paper or Mylar tape? Did you account for the weight reduction > due to chad removed? Paper, and no :-) John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] What does "CNC" really mean?
On Fri, Sep 2, 2016, at 07:29 AM, Bruce Layne wrote: > > > On 08/31/2016 10:22 PM, Gregg Eshelman wrote: > > Surprising that just for the fun of doing it, someone hasn't built a > > punched tape reader for a 3D printer. > > > Have you SEEN 10MB of paper tape?!? :-o > > The bits on paper tape are about .1" in diameter. That's a lot of paper > tape. 15.8 miles of paper actually. The spool would be over 35 inches in diameter and weigh 115 lbs. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Leadscrew Efficiency?
Are they LEADscrews or BALLscrews? With ballscrews, the finer pitch screw should indeed provide a much better mechanical advantage. With leadscrews, the mechanical advantage almost doesn't matter, because friction is by far the dominant force. Somewhere between 60% and 95% of the torque required to turn a leadscrew under load is due to the friction between the screw and nut rather than the force actually needed to raise the load. I'm not sure why the 10tpi screw would actually be worse - I would expect it to be roughly the same. However, many factors come into play: 1) materials: are both screws steel? both nuts bronze? (pr plastic, or whatever) The materials and lubrication can make a huge difference in the amount of friction. 2) surface quality: a rough screw or nut will have more friction than a polished one 3) thread form: 60 degree threads have a lot more friction than Acme due to the wedging action of the 60 degree flanks. Square threads are best because the flanks are perpendicular to the load, but Acme is almost as good. 4) diameter: if all of the above are equal, the friction FORCE will be the same. But the TORQUE required depends on the radius of the screw, so a larger diameter screw will require more torque. On Thu, Aug 18, 2016, at 10:14 AM, Todd Zuercher wrote: > I have a machine that I converted from step-motors to servos, and I'm having > a little trouble with the Z axis. It has an anti backlash lead screw with a > 5tpi screw. This sort of worked, but the servo was working hard to move the > head, and I wanted a little higher encoder resolution for better tuning. So I > swapped in a nearly identical 10tpi lead screw set I happened to have on hand > (removed from another stepper machine to get better speed and perfomance). I > thought that the 10tpi screw should be easier for the servo to turn, but I'm > finding that the opposite is true and the servo can't raise the motor without > counter balance assistance when it could with the 5tpi. Does that make sense, > or is the problem more likely that the 10tpi screw and nut are worn out and > binding? > > -- > > > > Todd Zuercher > mailto:zuerc...@embarqmail.com > > > -- > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] More news & ? from WV.
On Tue, Aug 16, 2016, at 01:54 PM, andy pugh wrote: > > Have you considered having a casting made? You seem to enjoy > woodworking, so pattern making shouldn't be too hard for you. > I think foundries that are willing to do one-off jobs for random guys off the street are far less common on this side of the pond. I did some searching on that topic a few years back and had zero luck. John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Wednesday, was Sunday afternoon news from WV. Wierdsville inc.
On Thu, Aug 11, 2016, at 03:11 PM, andy pugh wrote: > A chap I know made this one out of standard parts, which looks nice > > https://goo.gl/photos/NUgVGG3AeYKP23WU8 > Unnaturally clean in there -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohodev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curing Oven
With everyone pitching in on what they think is the best controller, I'll put my two cents in... If you are doing this as a learning exercise, or to get better with LinuxCNC, then by all means do it and enjoy. But if you just want a working oven, get a DIN temperature controller and move on with your life. Sub $20 https://www.amazon.com/AGPtek%C2%AE-Digital-Temperature-Controller-Alarm/dp/B005NGL5AK I haven't studied specs for that particular one, but there are tons of them out there with capabilities ranging from rudimentary to far better than you'll likely cook up unless you spend weeks writing code. John Kasunich -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Curing Oven
On Tue, Aug 2, 2016, at 02:56 PM, Curtis Dutton wrote: > Hi everyone, > > > I'm in the middle of designing a paint curing oven for my shop. I am going > to control it with linuxcnc. The oven only runs at 120 Degress Farenheight > ~ 50 Deg Celsius > No specific answers to your LinuxCNC questions, just a general reminder. If you are going to leave this oven unattended, you want some brute-force dirt-simple over temperature protection. Like a Klixon temperature switch and a contactor. No semiconductors, no software. True story: My former employer had a 40 deg C burn-in oven for testing small VFDs. Over a weekend, the solid-state relay used to control the heating element failed shorted. On Monday we found 6 drives whose plastic covers looked like something out of a Salvador Dali painting. -- John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] brass and warpage during machining.
On Tue, Aug 2, 2016, at 01:09 PM, Mark wrote: > On 08/02/2016 12:39 PM, Gene Heskett wrote: > > On Tuesday 02 August 2016 10:46:03 Mark wrote: > > > >>> Silly Q: Going online to the metals pedlars, C360 seems to be what > >>> 90% of the bar stock offered is. But regardless of the alloy, its > >>> all stated as not being heat treatable. Since extruded brass is > >>> called half-hard, or HO2, it can be played with in the oven (if its > >>> hot enough), but always to soften. > >>> > >>> Are they simply trying to head off the idiot that thinks ferrous and > >>> wonders why his stock is dead soft after he heat treated it like > >>> steel? > >>> > >>> Cheers, Gene Heskett > >> Gene, > >> > >> You can't "heat treat" brass/bronze/copper etc (non-ferrous) to > >> harden. You can only anneal those metals. They do, however, work > >> harden, which annealing takes away. > >> > >> Mark > > I know that, Mark. For many decades. :) > > > > Cheers, Gene Heskett > > Perhaps I'm not understanding your earlier questions then about heat > treating? > > > Mark I think Gene is questioning the suppliers who list brass as "not heat treatable". He's right - annealing is a treatment that involves heat, so yes, brass can be heat-treated. But since 99% of people think of "heat treating" and "hardening" as the same thing, the vendors are covering themselves. You can't harden brass by heat treating. Why don't they say that? Who knows? Who cares John Kasunich jmkasun...@fastmail.fm -- ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Semi OT: Can't measure Index pulse on encoder
On Tue, Jul 19, 2016, at 08:20 AM, Leonardo Marsaglia wrote: > Could it a disadvantage the use of a digital scope over an analog one?. I > remember talking about scoping half bridges for an induction heater and > somebody underscored the advantages of the analog scope over the digital in > some cases, wich is why some people recommend having both of them. If set to auto-trigger, neither scope is likely to detect an index pulse. In that situation, a digital with deep memory, slow sweep speed (or roll mode) and a glitch capture mode would do better than the analog. But the real answer is to switch from auto-trigger to normal trigger and set the trigger source and level appropriately so the scope will trigger ONLY when the pulse arrives. With the trigger properly configured, either analog or digital would be able to detect the index pulse, but the digital would give you a better look at it because of its effectively infinite persistence. Halscope cannot reliably detect ANY pulse shorter than its sample time. If sampling in the servo thread that is usually 1mS, index pulses are often much shorter than 1mS (depending on how fast the encoder shaft is turning). If you are using a hardware based encoder counter (Mesa or PPMC or other), the actual index pulse probably doesn't appear in HAL at all. What Halscope CAN do is look at index-enable which is driven high by motion during the homing sequence (or can be disconnected and manually driven high by a "setp") and goes low when the encoder driver detects an index pulse. -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Semi OT: Can't measure Index pulse on encoder
On Wed, Jul 13, 2016, at 03:57 PM, Leonardo Marsaglia wrote: > Hello Jon. > > Well, the encoders that are already installed on one of our machines are > labelled with the Index pulse. The thing is I can't read the pulse with > halscope for example. > > I just tried to use the home using only index pulse and apparently the > index pulse is working because the axis latches until it stops and it turns > always a single turn more or less eyeballing it. > > The strange thing is I that I can't trigger the scope with the index pulse > on LinuxCNC, and also I can't measure the index on my other encoders. I > guess I should try to wire them to a LinuxCNC pc and make home manually to > see if they work ok. In your original posting you said you couldn't detect the index pulse with a digital scope at 20nS. Now you say you can't detect it with Halscope. Those are two completely different things. As Peter said, if you are using hardware encoder counters (Mesa, PPMC, or any other), Halscope is very unlikely to see the actual index pulse. But that doesn't matter. If you want to look at things with Halscope look at the index-enable HAL signal. It will be set true by the motion controller when the homing sequence starts to look for an index, and then set false by the hardware encoder driver when the index is detected. If index-enable goes true and then never goes false, that points toward the index signal from the encoder not making it to the hardware encoder counter. That is when you dig out the real scope and look at the real signal on a real wire. > > > > 2016-07-13 14:29 GMT-03:00 Jon Elson <el...@pico-systems.com>: > > > On 07/13/2016 08:56 AM, Leonardo Marsaglia wrote: > > > Hello to all. > > > > > > We just tested some Heindenhain encoders and as happened with other > > > encoders we can't sense the index pulse. We tried to detect it with a 20 > > > nano seconds period on a digital scope but nothing happens. All the other > > > pulses are working perfect except the index one. > > > > > > I have to mention that this happened with other encoders too, but since > > we > > > didn't need to use them with index pulse on the other machines we just > > let > > > it that way and didn't worry about it. > > > > > > > > Well, if the scope does not trigger on it, and it triggers > > fine on the A and B, then it just isn't there! > > Now, of course, the index will only happen once per rev, so > > you have to make a full turn to see the pulse. > > Are you SURE these encoders actually have the index pulse? > > > > Jon > > > > > > -- > > What NetFlow Analyzer can do for you? Monitors network bandwidth and > > traffic > > patterns at an interface-level. Reveals which users, apps, and protocols > > are > > consuming the most bandwidth. Provides multi-vendor support for NetFlow, > > J-Flow, sFlow and other flows. Make informed decisions using capacity > > planning > > reports.http://sdm.link/zohodev2dev > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > -- > *Leonardo Marsaglia*. > -- > What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic > patterns at an interface-level. Reveals which users, apps, and protocols are > consuming the most bandwidth. Provides multi-vendor support for NetFlow, > J-Flow, sFlow and other flows. Make informed decisions using capacity planning > reports.http://sdm.link/zohodev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Help locating device.
On Tue, Jul 12, 2016, at 09:08 PM, Greg Bentzinger wrote: > Hi all; > > I have been pulling my hair out trying to find a simple 802.11# unit. > > What I need is a small module that takes RJ45 input and makes it a wireless > connection. > > Much like a USB wireless dongal. > > Think of it as an inline wireless adaptor, a single IP pass through not a > full router bridge. > > I want to mount a IP camera up on a power pole. This pole has my electric > meter and a conduit up to a junction box with motion activated flood lights, > so I have a place to install a power supply. Problem is this pole is out by > its lonesome and all lines out are in underground conduits so for this island > with power I need a wireless solution. It is a rough environment, temps from > -30F to 110F are possible here in Colorado. > > Power company is fine with me adding the equipment within +/- 18" of the > flood lights, however if I were to run any cables from the pole they would > have to be in underground conduits and that requires permits and underground > tracing to locate where all prior conduits are before digging. > > Everything I have been finding in my searches requires a USB interface - if > nothing else to supply power. Any ideas? Get one that uses USB only for power, cut the end off a USB cable and splice it to a 5V wall wart? -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Boring bar Q
I don't think there is really a standard. I would guess most would be either 45 degrees or 30 degrees. Stick an un-ground tool blank in the hole and measure it? John On Sun, Jul 3, 2016, at 12:05 PM, Gene Heskett wrote: > Greetings everybody; > > This Sheldon lathe came with a boring bar, .750" by about 8" long. One > end is broached straight thru for a small 1/4" tool, while the other is > broached at an angle. I am thinking the angled end would allow me to cut > threads about 1/2" closer to the bottom of a hole. But to do that, I'd > need to know this angle so it could be used in sharpening the tool > properly. > > Is there a std angle for this broached at an angle end of a boring bar? > > If so, what is the degree of that angle? > > Cheers, Gene Heskett -- Attend Shape: An AT Tech Expo July 15-16. Meet us at AT Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] ER-16 spindles
On Wed, Jun 29, 2016, at 12:39 PM, Gene Heskett wrote: > On Wednesday 29 June 2016 11:16:26 Ralph Stirling wrote: > > > Have any of you come across cheap collet spindles that > > have a through-bore? I am toying with an idea for a > > simple, special-purpose lathe, and need a hollow spindle. > > > > Thanks, > > -- Ralph > > Looking around on eBay for 5C collet kits, I stumbled over a 5C to ER40 > tool and a big box of ER40 collets. That adaptor claims to be bored > internally for stoppers, so I'd have to assume its bored thru. So if you > need less that its passthru, I'm guessing an inch or a few thou more, The original poster was looking for ER16, not ER40. Huge difference... > There are ER40 adaptors for lots of > smaller spindles but the 5C would probably be only one of two bored > thru, as I'd expect the R8-ER40 adaptor is too. R8 to anything adapter is highly unlikely to be bored thru. R8 uses a 7/16-20 drawbar thread, and a solid drawBAR not a hollow drawTUBE. -- John Kasunich jmkasun...@fastmail.fm -- Attend Shape: An AT Tech Expo July 15-16. Meet us at AT Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle control panel breaks LinuxCNC?
How is LinuxCNC connected to the VFD? Direct hardware control, with an analog speed command and start/stop signals from a parallel port? Or serial communications using a HAL driver specific to that brand of VFD? Or Modbus using the generic LinuxCNC HAL Modbus driver? Or Ethernet using ??? driver? That is critical information - I don't recall seeing it anywhere in this email chain, but maybe I missed something in the first message or two. The core of LinuxCNC (GUI and motion controller) doesn't communicate with the VFD at all. LinuxCNC reads and writes to HAL pins, and those pins are connected to some driver that in turn talks to the drive. So there are two things happening here: 1) The core of LinuxCNC manipulates the HAL pins differently when you use M3 or the MPG compared to when you use the on-screen buttons. 2) The driver and/or the VFD itself responds badly to the HAL pin activity from the on-screen buttons. I think the first step is to figure out item 1. Set up halscope to observe all the spindle-related HAL pins. Capture and save shots of it working correctly when driven by M3 or the MPG. Then capture it failing when driven by the on-screen button. Study the screen pictures and figure out what is different. Maybe the difference makes sense given the context, maybe it is a bug in the core of LinuxCNC. Post your findings. If the difference makes sense, then the problem is in the driver or the VFD. If we know exactly what driver you are using and how it is connected to the drive, and we know exactly what the HAL pins going into the driver are doing, maybe we can figure out what is wrong. -- John Kasunich jmkasun...@fastmail.fm -- Attend Shape: An AT Tech Expo July 15-16. Meet us at AT Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] ER-16 spindles
On Wed, Jun 29, 2016, at 11:26 AM, andy pugh wrote: > On 29 June 2016 at 16:16, Ralph Stirling <ralph.stirl...@wallawalla.edu> > wrote: > > Have any of you come across cheap collet spindles that > > have a through-bore? I am toying with an idea for a > > simple, special-purpose lathe, and need a hollow spindle. > > eBay is full of them. (well, not literally). > > http://www.ebay.co.uk/itm/301808141248 > Note that that auction does not specify the diameter of the thru-hole. My experience with similar collet chucks is that the hole is smaller than you expect, often smaller than the clamping diameter of the matching collets. In my case I've got ER20 collets and bought some 3/4" straight shank collet chucks. ER20 collets will hold up to 13mm (1/2"), but the thru-hole in the shank is more like 3/8" (9mm). How big of a thru-hole do you need? -- John Kasunich jmkasun...@fastmail.fm -- Attend Shape: An AT Tech Expo July 15-16. Meet us at AT Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Quiet?
On Wed, Jun 8, 2016, at 02:04 PM, Peter Blodow wrote: > Oh John, > for us over here "on the other side of the pond" it is exceedingly > interesting what is being said about Donald in his own country. We all > wonder who these Americans actually are that encourage him on his hate > campaign and may even elect him... Keep writing! Not on the LINUXCNC mailing list! -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Quiet?
On Wed, Jun 8, 2016, at 12:11 PM, Gene Heskett wrote: > Maybe, maybe not. Shrillaries victory speech last night came straight out > of Bernies socialist bible, and that scares the crap out of me, lots > more than the Donalds blowhard bluster. Guys, please. We have a fair amount of off-topic stuff on this list, and for the most part that's OK. But PLEASE, let's leave the politics out of it. Trump fans aren't going to convert Clinton fans, Clinton fans aren't going to convert Trump fans. But everyone will have to hear the discussions and the arguments and the name- calling. We're going to have enough (far too much) of that elsewhere for the next several months, lets not have it here. I'm not trying to single Gene out here. Once these things start they inevitably go downhill, and this one started several messages ago. Let's just not start. -- John Kasunich emc-users list admin -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] drive belt for 7x12 NOT OEM
On Thu, Jun 2, 2016, at 03:16 PM, Gene Heskett wrote: > On Thursday 02 June 2016 09:15:35 John Kasunich wrote: > > It sounds like part of the problem is a spindle pulley that > > is too small. That hurts twice. First, it reduces the lever > > arm and requires more belt pull per ft-lb of torque delivered. > > Second, it reduces the belt wrap and number of teeth engaged, > > which increases the load per tooth even more. > > > > Bigger pulleys help in other ways too. A big spindle pulley > > provides some flywheel effect which can reduce chatter > > and relieves the motor/belt of the worst shock loads. > > A larger upper pulley that drives the lathes head countershaft is not > possible as it runs into the rear of the spindle at about 1 more cog. > When I wrote that I was unaware that this lathe had gears inside the headstock and that the belt was driving the shaft with the gears rather than driving the spindle directly. I think your "bigger better lathe" approach is the right one. But if for some reason I was stuck with the 7x lathe, I would ignore the countershaft with its plastic gears and put a nice big pulley on the back of the main spindle -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] drive belt for 7x12 NOT OEM
On Thu, Jun 2, 2016, at 10:54 AM, andy pugh wrote: > > Clearly belts are not working, so what else is there? > Clearly the EXISTING belts are not working. They were designed for the original motor and original motor controller, and may well have been marginal for that application. I'm 99% sure Gene has changed both motor and controller. I know he's using Jon Elson's motor controller, with a much higher current rating. I'm pretty sure he's also using a much stronger motor. I wouldn't be surprised if he's doubled or even tripled the available peak torque. Now he has to uprate the drivetrain to match. I've seen toothed belts used to transmit 100HP (big belts on big pulleys). Certainly belts can do the job if sized properly. Industrial sized lathes (including yours I think) usually use a combination of belts and gears. Chains are very rare in lathe drivetrains. -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] drive belt for 7x12 NOT OEM
On Thu, Jun 2, 2016, at 09:45 AM, andy pugh wrote: > On 2 June 2016 at 14:15, John Kasunich <jmkasun...@fastmail.fm> wrote: > > Unless this is a mighty slow lathe, I don't think chain is the > > appropriate drive mechanism. > > Silent chain has been used on a number of lathes historically: > http://www.lathes.co.uk/southbend/page12.html That South Bend installation had a recommended motor speed of 900 RPM. Gene's lathe uses a motor that I think runs 4000 RPM. My Van Norman mill used a silent chain from the 1/4 HP 1800 RPM feed motor to the input shaft of the feed gearbox. Pulley and chain were both worn and the chain would climb out of the teeth and skip. There was enough meat on the large pulley that I could turn off the silent-chain teeth and re-cut XL timing belt teeth. I put an off-the-shelf XL pulley on the motor and back in service. > > And the cam-chain in my motorcycle runs up to 14,000 rpm. > Fully enclosed and oil lubricated. And properly engineered for the task. > A conventional roller chain might well not be as smooth as one might > like in a lathe application, though. > > I haven't posted this here yet: > https://www.youtube.com/watch?v=woU927Tqoo8 > This is my current project, which is using motorcycle cam-chains to > drive the ball screws as an experiment. How fast do the ballscrews turn? I don't doubt that a chain could be made to work, but on a lathe as small as Gene's I think it is far from the ideal solution. -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] drive belt for 7x12 NOT OEM
On Thu, Jun 2, 2016, at 12:34 AM, Gregg Eshelman wrote: > There's bound to be some roller chain size between that and bicycle chain, > which would be ideal for your application. Unless this is a mighty slow lathe, I don't think chain is the appropriate drive mechanism. It sounds like part of the problem is a spindle pulley that is too small. That hurts twice. First, it reduces the lever arm and requires more belt pull per ft-lb of torque delivered. Second, it reduces the belt wrap and number of teeth engaged, which increases the load per tooth even more. Bigger pulleys help in other ways too. A big spindle pulley provides some flywheel effect which can reduce chatter and relieves the motor/belt of the worst shock loads. I've never seen this lathe, only tried to parse Gene's written explanations. So I have no idea what the real limitations are as far as pulley size, belt width, etc. A photo or two of the spindle area would help. What are the real constraints on pulley size and drivetrain configuration? Also helpful would be the following: Motor rated power (hp or watts, at a particular speed) Motor rated speed (at which it develops rated HP) Motor speed range when used with the drive in question Desired spindle speed range >From that information, you can use online resources to determine the proper type and size of belt and the proper pulleys to design a reliable drivetrain. Once you know what you need, then you figure out how to make it fit. This chart is a good starting point. http://www.sdp-si.com/D265/HTML/D265T006.html Given the rated HP and the speed of the faster pulley it shows you which belt families can handle the power. Doing it any other way is bass-ackwards IMHO. It sounds like the existing belt is an XL series. According to the chart, the maximum power for an XL belt is about 1/2HP at 3450 RPM, about 1/3HP at 1750 RPM. And that assumes properly chosen belt widths (not 3/8") and pulley sizes. If you've increased the motor beyond those limits (or even close to them), there is simply no way it is going to be reliable. Another option instead of timing belts is multi-groove V-belts (J series). They have the advantage that you can make your own pulleys (if you have a working lathe). A spindle drive shouldn't need positive registration, so you don't really need toothed belts. -- John Kasunich jmkasun...@fastmail.fm -- What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Tool Marks?
On Tue, May 24, 2016, at 04:29 PM, Chris Albertson wrote: > Gene, > > I think you had a better answer then mine. I suspected resonance but > you found a few more sources of it. > > One question: Is vacuuming really better then blowing. My theory is > that I can at best only get one atmosphere of pressure difference with > a vacuum but a blower can have any amount of force, 3 or 4 atmosphere > (ok "Bar") is easy.I think a 100 PSI jet clears the dust better. > But I've never tried to rig any kind of tiny-size vacuum. > Blowing might be better for dislodging the dust, but most people don't want to blow MDF dust all over their shops. -- John Kasunich jmkasun...@fastmail.fm -- Mobile security can be enabling, not merely restricting. Employees who bring their own devices (BYOD) to work are irked by the imposition of MDM restrictions. Mobile Device Manager Plus allows you to control only the apps on BYO-devices by containerizing them, leaving personal data untouched! https://ad.doubleclick.net/ddm/clk/304595813;131938128;j ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Attachments/Pictures with Mailing List Posts?
On Tue, May 24, 2016, at 11:41 AM, Mark Johnsen wrote: > I never get the pictures or attachments that are sent. I'm sure it's my > setup w/ gmail, but I get the impression there are others who CAN 'see' the > pictures... I am very jealous of these all seers :-) > > -- next part -- > A non-text attachment was scrubbed... > Name: 0524160945.jpg > Type: image/jpeg > Size: 129321 bytes > Desc: not available > > -- > > Is there anyway I can get the picture? Am the only one w/ this issue? > That message must be coming from your mail supplier. LARGE attachments on the list are blocked, not stripped. (The entire message is held for moderation, the list admins either discard the whole thing if it's spam, or suggest a better way if it is legit.) Small attachments will get thru, but are not encouraged. It is better to post pictures somewhere else and link to them in your message. We don't want the list to be used to distribute spam or viruses Mark's email supplier is just another reason to not use attachments. John Kasunich (one of several list admins) -- Mobile security can be enabling, not merely restricting. Employees who bring their own devices (BYOD) to work are irked by the imposition of MDM restrictions. Mobile Device Manager Plus allows you to control only the apps on BYO-devices by containerizing them, leaving personal data untouched! https://ad.doubleclick.net/ddm/clk/304595813;131938128;j ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Plasma Mistake
On Thu, May 19, 2016, at 09:13 AM, Jim Craig wrote: > So my goal is to let others learn from my mistakes. So in that way I > tend to make a lot of them so everyone can benefit. Last night I was > working with the plasma machine and made a big one! > > Don't ever forget to hook up the ground to the plasma cutter! > > When we hit the go button the program started. The torch found the > material. The pilot arc started and BAM everything stopped. Realtime > error in LinuxCNC. Cleared repowered the machine and nothing would still > work. That is when I realized the ground clamp was not on the cutting > table. One question: Why do you have a ground "clamp". A CNC plasma is a more-or-less permanent installation. Put a lug on that ground cable and bolt it to the machine table/frame. -- John Kasunich jmkasun...@fastmail.fm -- Mobile security can be enabling, not merely restricting. Employees who bring their own devices (BYOD) to work are irked by the imposition of MDM restrictions. Mobile Device Manager Plus allows you to control only the apps on BYO-devices by containerizing them, leaving personal data untouched! https://ad.doubleclick.net/ddm/clk/304595813;131938128;j ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] SSR Issues, Thyristor dv/dt
On Tue, May 3, 2016, at 10:00 AM, andy pugh wrote: > If there is no reason not to leave the pre-charge relay closed during > operation, I could even use the existing mechanical relay that brings > in the discharge resistor. Is there a reason to switch-out the > precharge relay once the main contactor is closed? I guess the danger > is that if the main contactor fails to operate the machine would run > through the precharge resistor. Though I imagine that that would cause > an easily-detected undervoltage fault in the drives. You can certainly leave the pre-charge relay closed after closing the bypass (main) contactor. The vast majority of the AC drives on the market don't even have a pre-charge contactor. When power is applied, the bus immediately charges thru the resistor. The low voltage power supply for the electronics runs off the DC bus (great for power dip ride-thru.) Once the bus is up, the low-voltage power supply starts and the microcontroller comes alive. Then the micro-controller makes the decision to close the bypass contactor. If the bypass contactor opens during normal operation, the drive typically trips on low bus voltage. Although the worst case situation is a motor load that's not quite enough to drag the bus down to the low bus trip point, but is high enough to cook the pre-charge resistor. Pre-charge resistors are usually sized for intermittent duty, so they need to be a type that fails safely under continuous overload (no arcing or fire). On large (expensive) drives we sometimes use an auxiliary contact on the bypass contactor as an interlock. -- John Kasunich jmkasun...@fastmail.fm -- Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] SSR Issues, Thyristor dv/dt
On Tue, May 3, 2016, at 09:34 AM, andy pugh wrote: > On 3 May 2016 at 14:27, Erik Christiansen <dva...@internode.on.net> wrote: > > Yup, a MOV goes across the triac, to clamp voltage spikes. > > When you say "Across" do you mean across the output terminals of the > SSR, or between the live terminal of the SSR and neutral? > > The former is easier, and I doubt that there would be much trouble > caused by dumping the spikes into the main capacitor as long as the > rectifier wasn't too upset. A MOV across the SSR protects the SSR (only). A MOV across the input protects everything. However, the MOV across the SSR can potentially do a better job of protecting the SSR because the lead length is shorter and thus inductance is lower. At decent power levels (tens of kW and up) the main cap and rectifier can clamp most transients, so only the SSR is at risk. But small rectifiers can be destroyed by the peak currents that happen when the cap clamps an incoming transient. At a former employer they had to beef up the rectifiers on a sub-kW class drive for exactly that reason. As an aside, here is a blog posting about the power supply I built for a CNC project. There is a link to the complete schematic early in the text, and photos of the completed supply. http://jmkasunich.com/cgi-bin/blosxom/shoptask/power-input-01-11-07.html Note that the EMC filter and inductor after the rectifier are not absolutely required. I had them in my well-stocked junk box so I used them. The contactors and relays also came from junk. I think the only thing I bought was the disconnect switch (from Automation Direct). This particular supply is a bit unique in that I designed it to work as a voltage doubler on 120V, or as a bridge rectifier on 240V. -- John Kasunich jmkasun...@fastmail.fm -- Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] SSR Issues, Thyristor dv/dt
On Tue, May 3, 2016, at 06:42 AM, andy pugh wrote: > Section 6 on page C-343 here: > https://www.omron.com/ecb/products/pdf/precautions_ssr.pdf shows a > square-wave with zero time at 0 current. But I don't understand how > that is possible with a sinusoidal input voltage. Surely the current > is zero for all the period of the cycle where the input voltage is > less than the capacitor voltage? That picture shows an inductive load. And the text refers to solenoids which are inductive. A sufficiently large inductor will draw a nearly constant current with modest ripple at double the line frequency, which becomes a more-or-less square wave on the line side of the rectifier. > I wonder whether I would be better with DC-rated SSRs on the DC side > of the rectifier? > In case it helps, this is the input circuit. > https://imagebin.ca/v/2fs1b7szpsMy The SSRs are controlled by LinuxCNC > individually Is there any particular reason you are using SSRs instead of regular contactors? I like contactors because they are rugged and pretty much immune to overvoltage, dv/dt, and di/dt problems. Contactors (or electromechanical relays) also provide an air-gap between line power and the load, which means I'm comfortable using them in an e-stop circuit. SSRs (or any other semiconductor) are far more likely to fail shorted than open, and can't safely be used to disconnect power. Also, is there any particular reason you are running the full load current through both relays? I design large AC motor drives that rectify the AC line to make a DC bus. (Large is hundreds of kW). It would be prohibitively expensive to use two contactors sized for the full rated power. The precharge resistors are fed through a small contactor, rated (and fused) for the precharge current only (line voltage divided by resistor value). The bypass contactor is rated for full load current and bypasses the resistors. See the attached drawing "dc-supply-threephase.pdf" for an example. (The three 1.5uF caps are to absorb line-to-ground transients that couple across the distribution transformer from HV switching.) The other attached drawing is for a single-phase home-shop scale project. For home stuff. I use two poles for both precharge and bypass. American 240V consists of two lines, each 120V from ground, and for safety I need to disconnect both. I use the outer two poles of a three-pole contactor or relay. If British 240V has line and neutral then in theory you could use only one pole in the line side - but I personally would still use two. Most contactors have three poles anyway, might as well use them. At home-shop power levels, only the bypass device needs to be a contactor. The charging device can be a simple two-pole relay, like the ubiquitous ice-cube or KUP. -- John Kasunich jmkasun...@fastmail.fm dc-supply-precharge.pdf Description: Adobe PDF document dc-supply-threephase.pdf Description: Adobe PDF document -- Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Max acceleration/velocity (Limited by?)
On Sun, Apr 3, 2016, at 12:14 PM, Nicklas Karlsson wrote: > Then reading the configuration file I find there max acceleration and > velocity is defined twice. They are defined in both [TRAJ] and [AXIS_?] > sections. I am reasonably certain that the TRAJ limits apply to the combined motion of the controlled point, while the AXIS limits apply to the individual axes. Consider a 45 degree move. If X is moving at its limit of 10 units/sec and Y is also moving at its limit of 10 units/sec, the controlled point is moving at 14.14 units/sec. If the TRAJ limit was also 10, X and Y would be slowed down to 7.07 units/sec so that the controlled point is moving at 10. > > Does the trajectory planner follow the limit in it's own section? In such > case what happen if [AXIS_?] limit is lower? > I'm pretty sure lowest limit wins. Assume X limit is 6, Y limit is 8, and TRAJ limit is 9. A move from (0,0) to (10,0) is parallel to X and would be limited to 6. A move from (0,0) to (0,10) is parallel to Y and would be limited to 8. A move from (0,0) to (12,16) would result in X moving at 5.4 units/sec and Y moving at 7.2 units/sec, so that the motion of the controlled point is at 9 units/sec even though neither axis is at its limit. I am working from (ancient) memory - if knowing is important I would suggest making a config with different limits and conducting some experiments. G0 moves run at the limits (I think), and halscope or halmeter can be used to observe velocity. -- John Kasunich jmkasun...@fastmail.fm -- Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785471=/4140 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Rewire Question?
On Wed, Mar 16, 2016, at 01:26 PM, Todd Zuercher wrote: > Bringing back an older thread. Went to start ordering the things I need for > the update and noticed that the conduit to the machine isn't big enough for > the new wiring. Right now the 9 single phase circuits are run through two > 3/4" conduits (4 in one 5 in the other). would it be a really bad idea or > against regs, to split the 3ph wiring between the 2 conduits? (2+ground in > one and 1+nutral in the other) > Don't do it. Whenever you have a wire taking current to a load, the return path(s) for that load need to be in the same conduit. That means all three phases of a three-phase load, or phase and neutral for a single-phase load. The reason for this is that if both (single phase) or all three (three phase) wires are in the same conduit, the net current is zero and thus the magnetic field around the bundle of wires is zero If you don't have all the wires in one conduit, there is a net magnetic field, and it can induce circulating currents in the conduit. Even without conduit (or with plastic conduit), if you have un-matched cables running through holes in a steel enclosure wall you can induce eddy currents in the wall. At modest current levels you can get away with it, but it is bad practice. At high current levels the induced currents generate heat, and you can melt things. Regarding grounds - codes usually require that ground wires run in the same current as the load carrying wires. Putting the ground in another conduit adds inductance (due to the loop area formed, and aggravated if the conduit is steel). That inductance increases voltage drop and makes the ground less effective in the event of a short to ground at the load. -- John Kasunich jmkasun...@fastmail.fm -- Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231=/4140 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
